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PHP interview questions

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					PHP interview questions, Part 1
What are the differences between Get and post methods in form submitting, give the
case where we can use get and we can use post methods?

   1. Who is the father of PHP and explain the changes in PHP versions?
   2. How can we submit a form without a submit button?
   3. In how many ways we can retrieve the date in the result set of mysql using
       PHP?
   4. What is the difference between mysql_fetch_object and mysql_fetch_array?
   5. What is the difference between $message and $$message?
   6. How can we extract string ‗techinterviews.com ‗ from a string
       ‗http://www.techinterviews.com‘ using regular expression of PHP?
   7. How can we create a database using PHP and mysql?
   8. What are the differences between require and include, include_once?
   9. Can we use include (‖techinterviews.php‖) two times in a PHP page
       ―makeit.PHP‖?
   10. What are the different tables present in mysql, which type of table is
       generated when we are creating a table in the following syntax: create table
       employee(eno int(2),ename varchar(10)) ?
   11. Functions in IMAP, POP3 AND LDAP?
   12. How can I execute a PHP script using command line?
   13. Suppose your Zend engine supports the mode <? ?> Then how can u
       configure your PHP Zend engine to support <?PHP ?> mode ?
   14. Shopping cart online validation i.e. how can we configure Paypal, etc.?
   15. What is meant by nl2br()?
   16. Draw the architecture of Zend engine?
   17. What are the current versions of apache, PHP, and mysql?
   18. What are the reasons for selecting lamp (linux, apache, mysql, PHP) instead
       of combination of other software programmes, servers and operating
       systems?
   19. How can we encrypt and decrypt a data present in a mysql table using mysql?
   20. How can we encrypt the username and password using PHP?
   21. What are the features and advantages of object-oriented programming?
   22. What are the differences between procedure-oriented languages and object-
       oriented languages?
   23. What is the use of friend function?
   24. What are the differences between public, private, protected, static, transient,
       final and volatile?
   25. What are the different types of errors in PHP?
   26. What is the functionality of the function strstr and stristr?
   27. What are the differences between PHP 3 and PHP 4 and PHP 5?
   28. How can we convert asp pages to PHP pages?
   29. What is the functionality of the function htmlentities?
   30. How can we get second of the current time using date function?
   31. How can we convert the time zones using PHP?
   32. What is meant by urlencode and urldocode?
   33. What is the difference between the functions unlink and unset?
   34. How can we register the variables into a session?
   35. How can we get the properties (size, type, width, height) of an image using
       PHP image functions?

                                                                                     1
36. How can we get the browser properties using PHP?
37. What is the maximum size of a file that can be uploaded using PHP and how
    can we change this?
38. How can we increase the execution time of a PHP script?
39. How can we take a backup of a mysql table and how can we restore it. ?
40. How can we optimize or increase the speed of a mysql select query?
41. How many ways can we get the value of current session id?
42. How can we destroy the session, how can we unset the variable of a session?
43. How can we destroy the cookie?
44. How many ways we can pass the variable through the navigation between the
    pages?
45. What is the difference between ereg_replace() and eregi_replace()?
46. What are the different functions in sorting an array?
47. How can we know the count/number of elements of an array?
48. What is the PHP predefined variable that tells the What types of images that
    PHP supports?
49. How can I know that a variable is a number or not using a JavaScript?
50. List out some tools through which we can draw E-R diagrams for mysql.
51. How can I retrieve values from one database server and store them in other
    database server using PHP?
52. List out the predefined classes in PHP?
53. How can I make a script that can be bilanguage (supports English, German)?
54. What are the difference between abstract class and interface?
55. How can we send mail using JavaScript?




1.   chandu said,

     mysql_fetch_object() is similar to mysql_fetch_array(), with one difference -
     an object is returned, instead of an array. Indirectly, that means that you can
     only access the data by the field names, and not by their offsets (numbers
     are illegal property names).

     visit   http://in2.php.net/mysql_fetch_object
     and
     http://in2.php.net/mysql_fetch_array
     for more info

2.   chandu said,
     Answer for Q6) can be found at
     http://www.phpbuilder.com/columns/robert20000928.php3

3.   chandu said,
     Answer to Q7)

     $exploded[1] should have abc.com


                                                                                   2
4.   chandu said,
     answer to Q8)
     mysql_create_db() should work

5.   chandu said,
     Answer to Q9)
     require_once(),include_once() both the functions include and evalute the
     specified file only once
     and if the specified file is opened previous to the present call occurrance, it
     will not be done again.
     But require() and include() will do it as many times they are asked to do.

6.   chandu said,

     answer to q10) Yes we can include that many times we want, but here are
     some things to make sure of:
     (including abc.PHP, the file names are case-sensitive)
     there shouldnt be any duplicate function names, means there should not be
     functions or classes or variables with the same name in abc.PHP and
     makeit.php

7.   chandu said,
     correction to my previous comment:
     I‘v specified functions,classes and variables, exactly what I meant with
     variables is…u‘v to
     make sure that the variables wont over write each other.

8.   chandu said,

     Answer to Q)11
     Refer the Page
     http://dev.mysql.com/doc/mysql/en/storage-engines.html

9. meenakshi said,

     get is like query string all the variables will be displayed in he url
     where as post is the standard way of sending th evariables

10.meenakshi said,

     Ques 2
     Father of php is Rasmus Lerdorf and for version info and changes see this link
     http://www.php.net/ChangeLog-4.php#4.1.0

11.meenakshi said,


                                                                                       3
   q5
   mysql_fetch_object is like fetching value from a recordset
   and mysql_fetch_array is gettin array‘s value

12.sukhbir said,

   ans_16

   nl2br() inserts html in string

   echo nl2br(‖god bless \n you‖);

   output
   god bless
   you

13.D   R Jadav said,
   Answer for Q.1

   When we submit a form, which has the GET method it displays pair of
   name/value used in the form at the address bar of the browser preceded by
   url. Post method doesn‘t display these values.

14.D   R Jadav said,
   Answer of Question 1:When we submit a form, which has the GET method it
   displays pair of name/value used in the form at the address bar of the
   browser preceded by url. Post method doesn‘t display these values.

15.D   R Jadav said,
   Answer of Question no 5 :

   mysql_fetch_object() is similar to mysql_fetch_array(), with one difference -
   an object is returned, instead of an array. Indirectly, that means that you can
   only access the data by the field names, and not by their offsets (numbers
   are illegal property names). Note: Field names returned by this function are
   case-sensitive.
   field;
   /* this is invalid */
   echo $row->0;
   ?>

16.D   R Jadav said,
   Answer of question no 6:
   $message is variable whereas $$message is Dynamic variable.



                                                                                 4
  eg.
  $user=‖bob‖

  is equivalent to

  $holder=‖user‖;
  $$holder=‖bob‖;

17.D   R Jadav said,
  Answer of Question 7 :

  Use the function split split(―@‖,‖http://info@abc.com‖) which returns an array
  any second element of the returned array will hold the value as abc.com.

18.D   R Jadav said,
  Answer of Question no 8 :

  We can create MySQL database with the use of mysql_create_db(―Database‖)

19.D   R Jadav said,
  Answer of Question no 9 :

  The include_once() statement includes and evaluates the specified file during
  the execution of the script. This is a behavior similar to the include()
  statement, with the only difference being that if the code from a file has
  already been included, it will not be included again. The major difference
  between include() and require() is that in failure include produces a warning
  message whereas require produces a Fatal errors.

20.D   R Jadav said,
  Answer of Question no 10 :

  Yes we can use include() more than once in same page.

21.D   R Jadav said,
  Answer of Question no 11 :

  Table Types are
  · ISAM(Index Sequential Access Method)
  · MyISAM
  o Static
  o Dynamic
  o Compress


                                                                                  5
  ·   Merge
  ·   Heap (Fastest tables because it stores in to the RAM)
  ·   BDB
  ·   InnoDB (Transaction safe table)

  When you fire the above create query MySQL will create the Dynamic table.

22.D   R Jadav said,
  Answer of Question no 13 :

  13. How can I execute a PHP script using command line?
  Through php parse you can execute PHP script using command line. By
  default location of php parser is /var/www/html so set the path of this
  directory and just use as following
  #php sample.php

23.D   R Jadav said,
  Answer of Question no 16 :

  Returns string with ‖ inserted before all newlines

24.D   R Jadav said,
  Answer of Question no 18 :

  For information about latest version of Apache, Php and Mysql please visits
  the following sites respectively.

  www.apache.org
  www.php.net
  www.mysql.com

25.D   R Jadav said,
  Answer of Question no 21 :

  You can encrypt a password with the following
  Mysql>SET PASSWORD=PASSWORD(―Password‖);

26.D   R Jadav said,
  Answer of Question no 26 :

  Three are three types of errors 1) Fatal errors 2) Parser errors 3) Startup
  errors.


                                                                                6
27.D   R Jadav said,
   Answer of Question no 27 :

   string strstr ( string str1, string str2) this function search the string str1 for
   the first occurrence of the string str2 and returns the part of the string str1
   from the first occurrence of the string str2. This function is case-sensitive and
   for case-insensitive search use stristr() function.

28.D   R Jadav said,
   Answer of Question no 29 :

   You can download asp2php front end application from the site
   http://asp2php.naken.cc.

29.Praveen said,

   nl2br
   (PHP 3, PHP 4 )

   nl2br — Inserts HTML line breaks before all newlines in a string
   QUES TION 16
   string nl2br ( string string)

   Returns string with ‖ inserted before all newlines.

   this will output :
   foo isn‘t
   bar

30.Grant Harding said,

   Is it really in the best interest of both employers and job-seekers to have the
   answers for this available? If you can‘t answer many of these basic questions,
   I hope you aren‘t aiming for a job in the field. These simple answers come
   with experience and practice.

31.Shatabdi said,

   56. How can we send mail using JavaScript?
   The answer for this question

   function myfunction(form)
   {
   tdata=document.myform.tbox1.value;
   location=‖mailto:dep7abc@leeds.ac.uk?subject=‖+tdata+‖/MYFORM‖;
   return true;
   }


                                                                                    7
32.Shatabdi said,

   53.List out the predefined classes in PHP?
   Predefined Classes
   1. Standard Defined Classes
   These classes are defined in the standard set of functions included in the PHP
   build.

   a. Directory
   The class from which dir() is instantiated.

   b.stdClass

   2.Ming Defined Classes
   These classes are defined in the Ming extension, and will only be available
   when that extension has either been compiled into PHP or dynamically loaded
   at runtime.

   a.swfshape

   b. swffill

   c. swfgradient

   d. swfbitmap

   e. swftext

   f. swftextfield

   g. swffont

   h. swfdisplayitem

   i. swfmovie

   j. swfbutton

   k. swfaction

   l. swfmorph

   m. swfsprite

   3. Oracle 8 Defined Classes
   These classes are defined in the Oracle 8 extension, and will only be available
   when that extension has either been compiled into PHP or dynamically loaded
   at runtime.




                                                                                 8
   a. OCI-Lob
   b. OCI-Collection

   4. qtdom Defined Classes
   These classes are defined in the qtdom extension, and will only be available
   when that extension has either been compiled into PHP or dynamically loaded
   at runtime.

   a. QDomDocument

   b. QDomNode

33.Bharati Raul said,

   1) What are the differences between Get and post
   methods in form submitting, give the case where we can
   use get and we can use post methods?

   Ans : When you want to send short or small data,
   not containing ASCII characters, then you can use ―GET‖
   Method. But for long data sending say more then 100
   character you can use ―POST‖ method.

   Once most imp diff is when you are sending the form with
   ―Get‖ method. You can see the output which you are sending
   in the addressbar. Whereas if you send the form with ―POST‖
   method then user can not see that information.
   ————————————————–

   2) Who is the father of PHP and explain the changes in
   PHP versions?

   Ans : Rasmus Lerdorf is the father of PHP
   ————————————————–

   3) How can we submit a form without a submit button?

   Ans : I can submit a form in many ways, for e.g.
   1. When user click on checkbox, or drop down
   2. When user click on radio button
   3. At the end of the form I will type ―Click here
   to submit‖ & link text to the processing file
   ————————————————–

   4) In how many ways we can retrieve the date in
   the result set of mysql using PHP?

   ————————————————–
   5) What is the difference between mysql_fetch_object
   and mysql_fetch_array?


                                                                              9
   Ans :
   Speed-wise, the function is identical to mysql_fetch_array(),
   and almost as quick as mysql_fetch_row() (the difference is
   insignificant).

   mysql_fetch_object() is similar to mysql_fetch_array(),
   with one difference - an object is returned,
   instead of an array. Indirectly, that means that you can only
   access the data by the field names, and not by their offsets
   (numbers are illegal property names).
   ————————————————–

   6) What is the difference between $message and
   $$message?
   Ans : $message is variable whereas $$message is dynamic varibale
   ————————————————–

34.Bharati Raul said,

   7) How can we extract string ‗abc.com ‗ from a string
   ‗http://info@abc.com‘ using regular expression of PHP?
   Ans : echo substr(‖http://info@abc.com‖,12,19);
   ————————————————–

   8) How can we create a database using PHP and mysql?
   ANS : mysql_create_db(‖Database_Name‖);
   ————————————————–

   9) What are the differences between require and include, include_once?
   ANS :
   include() & require() - includes the file during the execution of the script.
   but is there is any problem include() generate a warning message where as
   require() generates the fatal error.
   include_once() & require_once() - same as include() and require() but
   if file is already included then does not produce any error or not
   include that file again
   ————————————————–

   10) Can we use include (‖abc.PHP‖) two times in a PHP
   page ―makeit.PHP‖?

   Ans : Yes we can include two times and more then two times also
   ————————————————–

   11) What are the different tables present in mysql,
   which type of table is generated when we are creating
   a table in the following syntax: create table
   employee(eno int(2),ename varchar(10)) ?

   Ans :
   Total 5 types of tables we can create


                                                                                   10
   1. MyISAM
   2. Heap
   3. Merge
   4. INNO DB
   5. ISAM
   MyISAM is the default storage engine as of MySQL 3.23.
   ————————————————–

35.Kumar said,

   What is meant by urlencode and urldocode?
   string urlencode(str)
   where str contains a string like this ―hello world‖ and the return value will be
   URL encoded and can be use to append with URLs, normaly used to appned
   data for GET like someurl.com?var=hello%world
   string urldocode(str)
   this will simple decode the GET variable‘s value
   Like it echo (urldecode($_GET_VARS[var])) will o/p ―Hello world‖

36.Kumar said,

   How can we destroy the cookie?
   Set the cookie in past

37.Kumar said,

   What is the difference between the functions unlink and unset?
   unlink is a function for file system handling. It will simply delete the file in
   context
   unset will set UNSET the variable. e.g

38.Kumar said,

   How can we register the variables into a session?
   session_register($ur_session_var);

39.Kumar said,

   How can we know the count/number of elements of an array?
   2 ways
   a) sizeof($urarray) This function is an alias of count()
   b) count($urarray)
   interestingly if u just pass a simple var instead of a an array it will return 1.

40.ramesh said,

   Q 20;

   AES_ENCRYPT() and AES_DECRYPT()

                                                                                       11
41.Mikhail     Esteves said,
   Question 56: This question is wrong. You aren‘t really ‘sending mail‘ when
   doing a ‗mailto‘ and so it‘s a misleading question… A smart candidate would
   just say ―It‘s not possible‖ and you may write him off.

42.Pujitha     Sendanayake said,
   some information about zend engine.

   http://www.mlinux.org/projects/present/zend/
   http://www.zend.com/zend/zend-engine-summary.php
   http://www.zend.com/store/products/zend-engine.php

43.Pujitha     Sendanayake said,
   Q46-

   eregi_replace() function is identical to ereg_replace() except that this ignores
   case distinction when matching alphabetic characters.

44.Pujitha     Sendanayake said,
   q47.
   Sorting functions in PHP,
   asort-http://www.php.net/manual/en/function.asort.php
   arsort-http://www.php.net/manual/en/function.arsort.php
   ksort-http://www.php.net/manual/en/function.ksort.php
   krsort-http://www.php.net/manual/en/function.krsort.php
   uksort-http://www.php.net/manual/en/function.uksort.php
   sort-http://www.php.net/manual/en/function.sort.php
   natsort-http://www.php.net/manual/en/function.natsort.php
   rsort-http://www.php.net/manual/en/function.rsort.php

45.Rahul Amrutkar said,

   Ans Q. 52 for this purpose we have first read the data from one server into
   session varaibles. and then connect to other server and simply insert the data
   into the database

46.Rahul Amrutkar said,

   Q. 6
   $message is simple variable.
   $$message is reference variable.

47.Mallu    Indian said,


                                                                                 12
Some answers may be wrong.
I got the job anyway, so shouldnt be completly crap. ;-)

puremango.co.uk

1. WHAT IS THE DIFFERENCE BETWEEN GET & POST?

Get is an Idompotent method. (Idompotent: The side-effects of N > 0
identical requests is the same as for a single request. The methods GET,
HEAD, PUT and DELETE share this property.)‖GET‖ is basically for just getting
(retrieving: quering db for data & retriving) data whereas ―POST‖ may involve
anything, like storing or updating data, or ordering a product, or sending E-
mail. In GET form data is to be encoded (by a browser) into a URL while the
latter means that the form data is to appear within a message body. For GET
in IE, Maximum URL Length Is 2,083 Characters in Internet Explorer
(Q208427) or approximatly 1k.

2. WHO IS THE FATHER OF PHP AND WHAT IS THE CURRENT IN PHP &
MYSQLVERSION?

Rasmus Lerdorf.
PHP 5.1. Beta
MySQL 5.0

3. HOW CAN WE SUBMIT A FORM WITHOUT A SUBMIT BUTTON?

form.submit();

4. IN HOW MANY WAYS WE CAN RETRIEVE THE DATE IN THE RESULT SET OF
MYSQL USING PHP?

mysql_fetch_array — Fetch a result row as an associative array, a numeric
array, or both
mysql_fetch_assoc — Fetch a result row as an associative array
mysql_fetch_object — Fetch a result row as an object
mysql_fetch_row — Get a result row as an enumerated array

5.WHAT IS THE DIFFERENCE BETWEEN MYSQL_FETCH_OBJECT AND
MYSQL_FETCH_ARRAY?

mysql_fetch_array — Fetch a result row as an associative ARRAY, a numeric
array, or both
mysql_fetch_object — Fetch a result row as an OBJECT

6. WHAT IS THE DIFFERENCE BETWEEN $MESSAGE AND $$MESSAGE?

$message is a variable
$$message is a variable variable.
A variable variable allows us to change the name of a variable dynamically.




                                                                              13
7. HOW CAN WE EXTRACT STRING ‗ABC.COM‘ FROM A STRING
‗HTTP://INFO@ABC.COM‘ USING REGULAR EXPRESSION OF PHP?

8. HOW CAN WE CREATE A DATABASE USING PHP AND MYSQL?

$sql = ‗CREATE DATABASE my_db‘;
if (mysql_query($sql, $link))
{
echo ―Database my_db created successfully\n‖;
}
else
{
echo ‗Error creating database: ‗ . mysql_error() . ―\n‖;
}

9. WHAT ARE THE DIFFERENCES BETWEEN REQUIRE AND INCLUDE,
INCLUDE_ONCE?

All three are used to an include file into the current page. It is faster than
include().
If the file is not present, require(), calls a fatal error, while in include() does
not.
The include_once() statement includes and evaluates the specified file during
the execution of the script. This is a behavior similar to the include()
statement, with the only difference being that if the code from a file has
already been included, it will not be included again. It des not call a fatal error
if file not exists. require_once() does the same as include_once(), but it calls
a fatal error if file not exists.

10. CAN WE USE INCLUDE (‖ABC.PHP‖) TWO TIMES IN A PHP PAGE
―MAKEIT.PHP‖?

YES

11. WHAT ARE THE DIFFERENT TABLES PRESENT IN MYSQL, WHICH TYPE OF
TABLE IS GENERATED WHEN WE ARE CREATING A TABLE IN THE FOLLOWING
SYNTAX: CREATE TABLE EMPLOYEE(ENO INT(2),ENAME VARCHAR(10)) ?

MyISAM: This is default. Based on Indexed Sequntial Access Method. The
above SQL will create a MyISA table.
ISAM : same
HEAP : Fast data access, but will loose data if there is a crash. Cannot have
BLOB, TEXT & AUTO INCRIMENT fields
BDB : Supports Transactions using COMMIT & ROLLBACK. Slower that others.
InoDB : same as BDB

12. FUNCTIONS IN IMAP, POP3 AND LDAP?

imap_body — Read the message body
imap_check — Check current mailbox



                                                                                14
imap_delete — Mark a message for deletion from current mailbox
imap_mail — Send an email message

13. HOW CAN I EXECUTE A PHP SCRIPT USING COMMAND LINE?

As of version 4.3.0, PHP supports a new SAPI type (Server Application
Programming Interface) named CLI which means Command Line Interface.

14. SUPPOSE YOUR ZEND ENGINE SUPPORTS THE MODE THEN HOW CAN U
CONFIGURE YOUR PHP ZEND ENGINE TO SUPPORT MODE ?

Its already supported.

15. WHAT IS MEANT BY NL2BR()?

Returns string with after inserting HTML line breaks before all newlines in a
string

16. HOW CAN WE ENCRYPT AND DECRYPT A DATA PRESENT IN A MYSQL
TABLE USING MYSQL?

AES_ENCRYPT(str,key_str) , AES_DECRYPT(crypt_str,key_str)

17. ENCRYPTION FUNCTIONS IS PHP

CRYPT()
MD5()

18. WHAT ARE THE DIFFERENCES BETWEEN PUBLIC, PRIVATE, PROTECTED,
STATIC, TRANSIENT, FINAL AND VOLATILE?

19. WHAT ARE THE DIFFERENT TYPES OF ERRORS IN PHP?

here are three basic types of runtime errors in PHP:

1. Notices: These are trivial, non-critical errors that PHP encounters while
executing a script - for example, accessing a variable that has not yet been
defined. By default, such errors are not displayed to the user at all - although
you can change this default behaviour.

2. Warnings: These are more serious errors - for example, attempting to
include() a file which does not exist. By default, these errors are displayed to
the user, but they do not result in script termination.

3. Fatal errors: These are critical errors - for example, instantiating an object
of a non-existent class, or calling a non-existent function. These errors cause
the immediate termination of the script, and PHP‘s default behaviour is to
display them to the user when they take place.

Internally, these variations are represented by twelve different error types


                                                                                15
20. WHAT IS THE FUNCTIONALITY OF THE FUNCTIONS STRSTR() AND
STRISTR()?

string strstr ( string haystack, string needle )
Returns part of haystack string from the first occurrence of needle to the end
of haystack.

$email = ‗user@example.com‘;
$domain = strstr($email, ‗@‘);
echo $domain; // prints @example.com

stristr() is the case insensitive version of strstr()

21. DIFFERENCE BETWEEN HTMLENTITIES() AND HTMLSPECIALCHARS()]

htmlspecialchars : Convert some special characters to HTML entities (Only the
most widley used)
htmlentities : Convert ALL special characters to HTML entities

22. WHAT IS MEANT BY URLENCODE AND URLDOCODE?

urlencode : Returns a string in which all non-alphanumeric characters except
-_. have been replaced with a percent (%) sign followed by two hex digits
and spaces encoded as plus (+) signs.

urldocode : Decodes URL-encoded string

23. WHAT IS THE DIFFERENCE BETWEEN THE FUNCTIONS UNLINK AND
UNSET?

unlink: is used to delete a file
unset is used to destroy an eralier declared variable

24. HOW CAN WE REGISTER THE VARIABLES INTO A SESSION?

$_SESSION[‘name‘] = ―Chinmay‖;

To destroy a session: unset($_SESSION[‘name‘]);

25. HOW CAN WE GET THE PROPERTIES (SIZE, TYPE, WIDTH, HEIGHT) OF
AN IMAGE USING PHP IMAGE FUNCTIONS?

getimagesize — Get the size of an image
image_type_to_extension — Get file extension for image type
imagesx — Get image width
imagesy — Get image height

26. UPLOAD FILE SIZE

In Php.ini file: upload_max_filesize integer


                                                                            16
The maximum size of an uploaded file.
When an integer is used, the value is measured in bytes.

27. HOW CAN WE INCREASE THE EXECUTION TIME OF A PHP SCRIPT?

Use set_time_limit(int) where int is the number of seconds for
execution of the script. If it‘s set to 0 it‘s unlimited. Default value
is 30.

28. HOW CAN WE TAKE A BACKUP OF A MYSQL TABLE AND HOW CAN WE
RESTORE IT. ?

To backup: BACKUP TABLE tbl_name[,tbl_name…] TO
‗/path/to/backup/directory‘
RESTORE TABLE tbl_name[,tbl_name…] FROM ‗/path/to/backup/directory‘

mysqldump: Dumping Table Structure and Data

Utility to dump a database or a collection of database for backup or for
transferring the data to another SQL server (not necessarily a MySQL server).
The dump will contain SQL statements to create the table and/or populate the
table.
-t, –no-create-info
Don‘t write table creation information (the CREATE TABLE statement).
-d, –no-data
Don‘t write any row information for the table. This is very useful if you just
want to get a dump of the structure for a table!

29. OPTIMISING QUERIES

First, one thing that affects all queries: The more complex permission system
setup you have, the more overhead you get.
If you do not have any GRANT statements done, MySQL will optimise the
permission checking somewhat. So if you have a very high volume it may be
worth the time to avoid grants. Otherwise, more permission check results in a
larger overhead.

30. COOKIES

setcookie(‖variable‖,‖value‖,‖time‖);

variable - name of the cookie variable
variable - value of the cookie variable
time - expiry time
Example: setcookie(‖test‖,$i,time()+3600);

Test - cookie variable name
$i - value of the variable ‗Test‘
time()+3600 - denotes that the cookie will expire after an one hour

31. HOW TO RESET/DESTROY A COOKIE

                                                                            17
   Reset a cookie by specifying expiry time
   Example: setcookie(‖test‖,$i,time()-3600); // already expired time

   Reset a cookie by specifying its name only
   setcookie(‖test‖);

   32. WHAT IS THE DIFFERENCE BETWEEN EREG_REPLACE() AND
   EREGI_REPLACE()?

   eregi_replace() function is identical to ereg_replace() except that this ignores
   case distinction when matching alphabetic characters

   33. WHAT TYPES OF IMAGES THAT PHP SUPPORTS?

   imagetypes — Return the image types supported by this PHP build
   This function returns a bit-field corresponding to the image formats supported
   by the version of GD linked into PHP. The following bits are returned,
   IMG_GIF | IMG_JPG | IMG_PNG | IMG_WBMP | IMG_XPM. To check for PNG
   support, for example, do this: Example 1. imagetypes() example

   34. CHECK IF A VARIABLE IS INTEGER IN JAVASCRIPT

   var myValue =9.8;
   if(parseInt(myValue)== myValue)
   alert(‘Integer‘);
   else
   alert(‘Not‘);

   35. TOOLS USED FOR DRAWING ER DIAGRAMS.

   Case Studio
   Smart Draw

48.matts said,

   None of you got the Q7 right… you need to pay attention
   the question clearly satates that a _regex_ has to be used….

49.mahesh said,

   I got most of these questions when i attended a interview at brainay
   consulting, hyd. too many on regex. what is it?

50.u24 said,

   eek.. my php was removed.. ah well.

51.Richa said,



                                                                                 18
   Q. How can we increase the execution time of a PHP script?
   ans. By the use of void set_time_limit ( int seconds)
   Set the number of seconds a script is allowed to run. If this is reached, the
   script returns a fatal error. The default limit is 30 seconds or, if it exists, the
   max_execution_time value defined in the php.ini. If seconds is set to zero, no
   time limit is imposed.

   When called, set_time_limit() restarts the timeout counter from zero. In other
   words, if the timeout is the default 30 seconds, and 25 seconds into script
   execution a call such as set_time_limit(20) is made, the script will run for a
   total of 45 seconds before timing out.

   Q. How can I know that a variable is a number or not using a JavaScript?
   ans. bool is_numeric ( mixed var)
   Returns TRUE if var is a number or a numeric string, FALSE otherwise.

   Q.How can I execute a PHP script using command line?
   ans . Check the following url: http://www.sitepoint.com/article/php-
   command-line-1

   Q.What is meant by nl2br()?
   ans. nl2br — Inserts HTML line breaks before all newlines in a string
   Description
   string nl2br ( string string)

   Returns string with ‖ inserted before all newlines.

   Note: Starting with PHP 4.0.5, nl2br() is now XHTML compliant. All versions
   before 4.0.5 will return string with ‖ inserted before newlines instead of ‖.

   Example 1. using nl2br()

   this will output :

   foo isn‘t
   bar

52.Subir said,

   Ans (14)

   In php.ini file:

   set

   short_open_tag=on

   to make PHP support

53.parmanand said,

                                                                                    19
   any on can tell me how can we recieve textfield valu on next page in php
   when set global off for security purpuse, without usin GET POST REQUEST
   HTTP_VARS global arrays

54.Viral Hirpara said,

   Question No. 7

   Answer,

   preg_match(‖|[^@]*@(.*)|im‖, $text, $output);

   $output will give result in second index of array, means $output[1] is answer.

55.Arvind said,

   For Q#1

   What are "Get" and "Post"?
   Get and Post are methods used to send data to the server: With the Get
   method, the browser appends the data onto the URL. With the Post method,
   the data is sent as "standard input."
   Major Difference
   In simple words, in POST method data is sent by standered input
   (nothing
   shown in url when posting while in GET method data is sent through
   query string.
   ex:
   Assume we are logging in with username and password.
   GET: we are submitting a form to login.php, when we do ‘submit‘ or similar
   action to post the form values are sent through ‗visible‘ query string (notice
   ‗../login.php?username&password‘ as url when executing the script
   login.php)and
   is retrieved by login.php by $_GET[‘username‘] and $_GET[‘password‘].
   POST :we are submitting a form to login.php, when we do ‘submit‘ or
   similar action to post the form, values are sent through ‗invisible‘ standered
   input (notice ‗../login.php‘) and is retrieved by login.php by
   $_POST[‘username‘]
   and $_POST[‘password‘].
   POST is assumed more secure and we can send lot more data than that of
   GET
   method is limited(they say Internet Explorer can take care of maximum 2083
   character
   as a query string).

56.Satnam said,

   Wow, wonderful answers on php questions. This is really helpful for the php
   candidates willing to appear for an interview



                                                                                 20
57.PHP    interview questions < TechInterviews.com said,
   […] I am trying to assign a variable the value of 0123, but it keeps coming up
   with a different number, what‘s the problem? - PHP Interpreter treats
   numbers beginning with 0 as octal. Look at the similar PHP interview
   questions for more numeric problems. […]

58.ShailC said,

   HI I am working on a website and am trying to make an online survey
   using PHP and MySQL.
   I have a few problems:
   1. A requirement for the survey is that it asks questions in several pages (first
   a set of 5 Qs and then click Continue and then again next 5 and again
   Continue and so on)
   I know how to send data to database and the values to different colomns but
   I dont know how to send data to same row for one person….once it goes to
   next page (on clicking continue) the data is sent into a new row and rest of
   the fields that were filled on previous page are left blank.
   Please let me know how to send the data to same row till one whole cycle is
   completed and start sending data to new row when a new user starts the
   survey.
   2. I need PHP script for reading the top ten values and minimum ten values of
   a colomn and take their average.
   3. I also want script for rating on scale of 1-7 and yes no percentage.

   I would be very thankful if some1 can provide me technical help regarding
   this.

   Thanks a lot

59.Ashik    Rahman said,

   preg_match(‖/^(http:\/\/)?([^\/]+)/i‖,
   ―info@abc.com‖, $matches);
   $host = $matches[2];
   preg_match(‖/[^\@.\/]+\.[^\.\/]+$/‖, $host, $matches);
   echo ―domain name is: {$matches[0]}\n‖;

60.shyambabu said,

   6th question answer is $message and $$message
   both are variable declarations.
   $message=‖ValueA‖
   $$message is equal to $($message)=$ValueA

61.tarangini said,

   Many of these questions i faced in interview when i attend an interview in
   technofy .These questions r very usefull to us.


                                                                                 21
62.Vikas Bhambi said,

   These are really ―Short BUT Sufficient‖ answers on php questions. It is really
   helpful for the Freshers willing to appear for an interview for PHP.

63.Slava said,

   How can we extract string ‗abc.com ‗ from a string ‗http://info@abc.com‘
   using regular expression of PHP?

   preg_match(‘/^http:\/\/.+@(.+)$/‘,'http://info@abc.com‘,$found);
   echo $found[1];

64.Slava said,

   How can we register the variables into a session?

   $_SESSION[‘var‘] = ‗value‘;

   Old way (deprecated):
   $var = ‗value‘;
   session_register(‘var‘);

65.PHP    Docs said,
   How can I execute a PHP script using command line?

   #php -F

66.Carrie    Underwood said,
   56. How can we send mail using JavaScript?

   document.sendeamil.submit();

67.Carrie    Underwood said,
   56. How can we send mail using JavaScript?

   document.sendeamil.submit();

68.Carrie    Underwood said,
   50. How can I know that a variable is a number or not using a JavaScript?

   Definition and Usage
   The isNaN() function is used to check if a value is not a number.


                                                                                22
  Syntax
  isNaN(number)

  Parameter Description
  number Required. The value to be tested

69.Jesse said,

  Q7)

  preg_match(‖/^(http:\/\/info@)?([^\/]+)/i‖,‖http://info@abc.com‖, $data);
  echo $data[2];

70.Mohammed Ismail said,

  Question :

  Difference between mysql_connect and mysql_pconnnect

71.skonealone said,

  Hi all..
  here are the answer for most of the questions post..

  1. What are the differences between Get and post methods in form
  submitting, give the case where we can use get and we can use post
  methods?
  Ans :-
  In the get method the data made available to the action page ( where data is
  received ) by the URL so data can be seen in the address bar. Not advisable if
  you are sending login info like password etc. In the post method the data will
  be available as data blocks and not as query string in case of get method.

  2. Who is the father of php and explain the changes in php versions?
  Ans :-
  Rasmus Lerdorf for version changes goto http://php.net/

  3. How can we submit from without a submit button?
  Ans:-
  Trigger the JavaScript code on any event ( like onselect of drop down list box,
  onfocus, etc ) document.myform.submit();This will submit the form.

  4. How many ways we can retrieve the date in result set of mysql using php?
  Ans:-
  As individual objects so single record or as a set or arrays.

  5. What is the difference between mysql_fetch_object and
  mysql_fetch_array?
  Ans:-


                                                                               23
MySQL fetch object will collect first single matching record where
mysql_fetch_array will collect all matching records from the table in an array

6. What is the difference between $message and $$message?
Ans:-
Both are variables only
$message is a variable and if used with print statement, the content of the
$message variable will be displayed. Where as with $$message variable, the
content of the $message will also be treated as variable and the content of
that variable will be displayed. For ex: If $message contains ―var‖, then it
displays the content of $var on the screen.

7. How can we extract string ‗abc.com ‗ from a string ‗http://info@abc.com‘
using regular _expression of php?
Ans:-
preg_match(‖/^(http:\/\/info@)?([^\/]+)/i‖,‖http://info@abc.com‖, $data);
echo $data[2];

Use the function split split(―@‖,‖http://info@abc.com‖) which returns an array
any second element of the returned array will hold the value as abc.com.

8. How can we create a database using php and mysql?
Ans:-
mysql_create_db()

9. What are the differences between require and include, include_once?
Ans:-
File will not be included more than once.
If we want to include a file once only and further calling of the file will be
ignored then we have to use the PHP function include_once(). This will
prevent problems with function redefinitions, variable value reassignments,
etc.

10. Can we use include (‖abc.php‖) two times in a php page ―makeit.php‖?
Ans:-
Yes we can include..

11. What are the different tables present in mysql, which type of table is
generated when we are creating a table in the following syntax: create table
employee(eno int(2),ename varchar(10)) ?
Ans:-
Total 5 types of tables we can create
1. MyISAM
2. Heap
3. Merge
4. INNO DB
5. ISAM
MyISAM is the default storage engine as of MySQL 3.23.

Table Types are
· ISAM(Index Sequential Access Method)
· MyISAM

                                                                                 24
o Static
o Dynamic
o Compress
· Merge
· Heap (Fastest tables because it stores in to the RAM)
· BDB
· InnoDB (Transaction safe table)

When you fire the above create query MySQL will create the Dynamic table.
http://dev.mysql.com/doc/mysql/en/storage-engines.html
MyISAM Table Type is created, if u not specified any table type then default
will be applied and MyISAM is default

13. How can I execute a PHP script using command line?
Ans:-
Through php parse you can execute PHP script using command line. By
default location of php parser is /var/www/html so set the path of this
directory and just use as following
#php sample.php

16. What is meant by nl2br()?
Ans:-
nl2br() inserts html in string
echo nl2br(‖god bless \n you‖);

output–
god bless
you

Returns string with ‗‘ inserted before all newlines

20. How can we encrypt and decrypt a data present in a mysql table using
mysql?
Ans:-
AES_ENCRYPT() and AES_DECRYPT()

21. How can we encrypt the username and password using PHP?
Ans:-
You can encrypt a password with the following
Mysql>SET PASSWORD=PASSWORD(‖Password‖);

26. What are the different types of errors in PHP?
Ans:-
Three are three types of errors 1) Fatal errors 2) Parser errors 3) Startup
errors.

27. What is the functionality of the function strstr and stristr?
Ans:-
string strstr ( string str1, string str2) this function search the string str1 for
the first occurrence of the string str2 and returns the part of the string str1



                                                                                     25
from the first occurrence of the string str2. This function is case-sensitive and
for case-insensitive search use stristr() function.

28. What are the differences between PHP 3 and PHP 4 and PHP 5?
Ans:-
for this ans goto http://php.net and check the version changes

29. How can we convert asp pages to PHP pages?
Ans:-
You can download asp2php front end application from the site
http://asp2php.naken.cc.

33. What is meant by urlencode and urldocode?
Ans:-
string urlencode(str)
where str contains a string like this ―hello world‖ and the return value will be
URL encoded and can be use to append with URLs, normaly used to appned
data for GET like someurl.com?var=hello%world
string urldocode(str)
this will simple decode the GET variable‘s value
Like it echo (urldecode($_GET_VARS[var])) will output ―Hello world‖

34. What is the difference between the functions unlink and unset?
Ans:-
unlink is a function for file system handling. It will simply delete the file in
context
unset will set UNSET the variable. e.g

35. How can we register the variables into a session?
Ans:-
Yes we can
session_register($ur_session_var);

42. How many ways can we get the value of current session id?
ans:-
session_id() returns the session id for the current session.

43. How can we destroy the session, how can we unset the variable of a
session?
Ans:-
session_unregister — Unregister a global variable from the current session
session_unset — Free all session variables

44. How can we destroy the cookie?
Ans:-
Set the cookie in past

45. How many ways we can pass the variable through the navigation between
the pages?
Ans:-
GET or QueryString and POST

                                                                                   26
46. What is the difference between ereg_replace() and eregi_replace()?
Ans:-
eregi_replace() function is identical to ereg_replace() except that this ignores
case distinction when matching alphabetic characters.eregi_replace() function
is identical to ereg_replace() except that this ignores case distinction when
matching alphabetic characters.

47. What are the different functions in sorting an array?
Ans:-
Sorting functions in PHP,
asort-http://www.php.net/manual/en/function.asort.php
arsort-http://www.php.net/manual/en/function.arsort.php
ksort-http://www.php.net/manual/en/function.ksort.php
krsort-http://www.php.net/manual/en/function.krsort.php
uksort-http://www.php.net/manual/en/function.uksort.php
sort-http://www.php.net/manual/en/function.sort.php
natsort-http://www.php.net/manual/en/function.natsort.php
rsort-http://www.php.net/manual/en/function.rsort.php

48. How can we know the count/number of elements of an array?
Ans:-
2 ways
a) sizeof($urarray) This function is an alias of count()
b) count($urarray)
interestingly if u just pass a simple var instead of a an array it will return 1.

53. List out the predefined classes in PHP?
Ans:-
1. Standard Defined Classes
These classes are defined in the standard set of functions included in the PHP
build.

a. Directory
The class from which dir() is instantiated.

b.stdClass

2.Ming Defined Classes
These classes are defined in the Ming extension, and will only be available
when that
extension has either been compiled into PHP or dynamically loaded at
runtime.

a.swfshape

b. swffill

c. swfgradient

d. swfbitmap



                                                                                    27
e. swftext

f. swftextfield

g. swffont

h. swfdisplayitem

i. swfmovie

j. swfbutton

k. swfaction

l. swfmorph

m. swfsprite

3. Oracle 8 Defined Classes
These classes are defined in the Oracle 8 extension, and will only be available
when
that extension has either been compiled into PHP or dynamically loaded at
runtime.

a. OCI-Lob
b. OCI-Collection

4. qtdom Defined Classes
These classes are defined in the qtdom extension, and will only be available
when that
extension has either been compiled into PHP or dynamically loaded at
runtime.

a. QDomDocument

b. QDomNode

56. How can we send mail using JavaScript?
Ans:-
No You can‘t send mail using Javascript but u can execute a client side email
client to send the email using mailto: code.

Using clientside email client
function myfunction(form)
{
tdata=document.myform.tbox1.value;
location=‖mailto:mailid@domain.com?subject=‖+tdata+‖/MYFORM‖;
return true;
}



                                                                               28
   This question is wrong. You aren‘t really ‘sending mail‘ when doing a ‗mailto‘
   and so it‘s a misleading question… A smart candidate would just say ―It‘s not
   possible‖ and you may write him off.

   57. What is meant by PEAR in php?
   Ans:-
   PEAR is the next revolution in PHP. This repository is bringing higher level
   programming to PHP. PEAR is a framework and distribution system for
   reusable PHP components. It eases installation by bringing an automated
   wizard, and packing the strength and experience of PHP users into a nicely
   organised OOP library. PEAR also provides a command-line interface that can
   be used to automatically install ―packages‖

   58. What is the purpose of the following files having extensions 1) frm 2) MYD
   3) MYI. What these files contains?
   Ans:-
   In MySql, the default table type is MyISAM.
   Each MyISAM table is stored on disk in three files. The files have names that
   begin with the table name and have an extension to indicate the file type.
   The `.frm‘ file stores the table definition.
   The data file has a `.MYD‘ (MYData) extension.
   The index file has a `.MYI‘ (MYIndex) extension,

   well i tryed myself to answer most of the questions..and may be u may get
   more robost answer for these questions..
   now u can have little idea abt the php frm these answers…
   and if u hv better answer dan i posted pls email me at
   skone.sk@gmail.com
   regards
   -skonealone ( shekhar koli)

72.Nosherwan Adil said,

   Q8.How can we extract string ‗abc.com ‗ from a string ‗http://info@abc.com‘
   using regular expression of PHP?

   $ext = strrchr(‗http://info@abc.com‘ , ‗@‘ );
   //output will be abc.com

73.Priya said,

   I am really satisfied with the questions and the different answers given.This
   can be of great help for people looking for a bulk of questions to be asked in
   interviews.
   Thankyou

74.Nithin said,

   Question 27: What is the functionality of the function strstr and stristr?
   strstr function used to find first occurrence of a string
   ex:

                                                                                29
   stristr function is an Case-insensitive strstr
   ex:

75.jeeva arulraj said,

   I am really satisfied with the questions and the different answers given.it will
   be more useful for people who are seeking php jobs and useful for the
   interviews.but two many answers make the readers more confusion.
   Thankyou

76.Archana said,

   Answer to Q. 13.

   PHP can be executed from Command Line, using the SAP Interface (SAPI) or
   Server Application Programming Interface named CLI which means Command
   Line Interface.
   The CLI SAPI was released for the first time with PHP 4.2.0, but was still
   experimental and had to be explicitly enabled with –enable-cli when running
   ./configure. Since PHP 4.3.0 the CLI SAPI is no longer experimental and the
   option –enable-cli is on by default. You may use –disable-cli to disable it.

77.parth said,

   tell me about Undefined offset when i use do & while loop
   $count=0;
   do
   {
   echo‖The enter Name of your child is‖.$_POST[‖child‖][$count].‖";
   $child_name=$_POST[‖child‖][$count];
   //echo $child_name;
   $count=$count+1;
   } while($child_name>= 0);
   where Child[] takenas array

78.Nitesh said,

   Q. 3. How can we submit a form without a submit button?

   Answer:
   We can submit a from without a submit button help ho javascript like.

   <a href=‖void(0)‖ rel=‖nofollow‖>Submit Me</a>

79.Nitesh said,

   Ans of 3. We can submit a form without a submit button with javascript.

80.Nitesh said,



                                                                                  30
   Ans of 3. We can submit a form without a submit button with the help of
   javascript.

81.Nitesh said,

   Ans of 1: When we submit a form, which has the GET method it pass value in
   the form of query string (set of name/value pair) and display along with URL.
   With GET we can a small data submit from the form (a set of 255 character)
   whereas Post method doesn‘t display value with URL. It passes value in the
   form of Object and we can submit large data from the form.

82.admin said,

   R.Karuppaiah
   Team Leader
   I Tech Indis (p) Ltd Chennai, India.
   Website: http://www.itechindia.com
   Email: iam_karu@yahoo.co.in
   Mobile: 91-9841467284

   1. What are the differences between GET and POST methods in form
   submitting, give the case where we can use get and we can use post
   methods?

   On the server side, the main difference between GET and POST is where the
   submitted is stored. The $_GET array stores data submitted by the GET
   method. The $_POST array stores data submitted by the POST method.

   On the browser side, the difference is that data submitted by the GET method
   will be displayed in the browser‘s address field. Data submitted by the POST
   method will not be displayed anywhere on the browser.

   GET method is mostly used for submitting a small amount and less sensitive
   data. POST method is mostly used for submitting a large amount or sensitive
   data.

   2. Who is the father of php and explain the changes in php versions?

   Rasmus Lerdorf for version changes go to http://php.net/ Marco Tabini is
   the founder and publisher of php|architect.

   3. How can we submit from without a submit button?

   We can use a simple JavaScript code linked to an event trigger of any form
   field. In the JavaScript code, we can call the document.form.submit() function
   to submit the form. For example:

   4. How many ways we can retrieve the date in result set of mysql Using php?

   As individual objects so single record or as a set or arrays.

                                                                              31
5. What is the difference between mysql_fetch_object and
mysql_fetch_array?

MySQL fetch object will collect first single matching record where
mysql_fetch_array will collect all matching records from the table in an array.

6. What is the difference between $message and $$message?

They are both variables. But $message is a variable with a fixed name.
$$message is a variable who‘s name is stored in $message. For example, if
$message contains "var", $$message is the same as $var.

7. How can we extract string ‗abc.com ‗ from a string ‗http://info@a…‘ using
regular _expression of php?

We can use the preg_match() function with "/.*@(.*)$/" as the regular
expression pattern. For example:
preg_match("/.*@(.*)$/","http://info@abc.com",$data); echo $data[1];

8. How can we create a database using php and mysql?

PHP: mysql_create_db()
Mysql: create database;

9. What are the differences between require and include, include_once?

File will not be included more than once. If we want to include a file once only
and further calling of the file will be ignored then we have to use the PHP
function include_once(). This will prevent problems with function
redefinitions, variable value reassignments, etc.

10. Can we use include ("abc.php") two times in a php page "makeit.php"?

Yes we can include..

11. What are the different tables present in mysql, which type of table is
generated when we are creating a table in the following
syntax: create table employee(eno int(2),ename varchar(10)) ?

Total 5 types of tables we can create

1. MyISAM

2. Heap

3. Merge

4. InnoDB

5. ISAM

                                                                              32
6. BDB
MyISAM is the default storage engine as of MySQL 3.23.

12. Functions in IMAP, POP3 AND LDAP?

Please visit:
http://fi2.php.net/imap
http://uk2.php.net/ldap

13. How can I execute a php script using command line?

Just run the PHP CLI (Command Line Interface) program and provide the PHP
script file name as the command line argument. For example, "php
myScript.php", assuming "php" is the command to invoke the CLI program.
Be aware that if your PHP script was written for the Web CGI interface, it may
not execute properly in command line environment.

14. Suppose your ZEND engine supports the mode Then how can u configure
your php ZEND engine to support mode ?

If you change the line: short_open_tag = off in php.ini file. Then your php
ZEND engine support only mode.

15. Shopping cart online validation i.e. how can we configure the paypals?

16. What is meant by nl2br()?

nl2br — Inserts HTML line breaks before all newlines in a string string nl2br
(string); Returns string with ‖ inserted before all newlines. For example: echo
nl2br("god bless\n you") will output "god bless \n you" to your browser.

17. Draw the architecture of ZEND engine?

18. What are the current versions of apache, php, and mysql?

PHP: php5.1.2
MySQL: MySQL 5.1
Apache: Apache 2.1

19. What are the reasons for selecting lamp (Linux, apache, mysql, php)
instead of combination of other software programs, servers and operating
systems?

All of those are open source resource. Security of linux is very very more than
windows. Apache is a better server that IIS both in functionality and security.
Mysql is world most popular open source database. Php is more faster that
asp or any other scripting language.

20. How can we encrypt and decrypt a data present in a mysql table using
mysql?

                                                                              33
AES_ENCRYPT () and AES_DECRYPT ()

21. How can we encrypt the username and password using php?

You can encrypt a password with the following Mysql>SET
PASSWORD=PASSWORD("Password");
We can encode data using base64_encode($string) and can decode using
base64_decode($string);

22. What are the features and advantages of OBJECT ORIENTED
PROGRAMMING?

One of the main advantages of OO programming is its ease of modification;
objects can easily be modified and added to a system there by reducing
maintenance costs. OO programming is also considered to be better at
modeling the real world than is procedural programming. It allows for more
complicated and flexible interactions. OO systems are also easier for non-
technical personnel to understand and easier for them to participate in the
maintenance and enhancement of a system because it appeals to natural
human cognition patterns.
For some systems, an OO approach can speed development time since many
objects are standard across systems and can be reused. Components that
manage dates, shipping, shopping carts, etc. can be purchased and easily
modified for a specific system.

23. What are the differences between PROCEDURE ORIENTED LANGUAGES
and OBJECT ORIENTED LANGUAGES?

Traditional programming has the following characteristics:

Functions are written sequentially, so that a change in programming can
affect any code that follows it.
If a function is used multiple times in a system (i.e., a piece of code that
manages the date), it is often simply cut and pasted into each program (i.e.,
a change log, order function, fulfillment system, etc). If a date change is
needed (i.e., Y2K when the code needed to be changed to handle four
numerical digits instead of two), all these pieces of code must be found,
modified, and tested.
Code (sequences of computer instructions) and data (information on which
the instructions operates on) are kept separate. Multiple sets of code can
access and modify one set of data. One set of code may rely on data in
multiple places. Multiple sets of code and data are required to work together.
Changes made to any of the code sets and data sets can cause problems
through out the system.

Object-Oriented programming takes a radically different approach:

Code and data are merged into one indivisible item – an object (the term
"component" has also been used to describe an object.) An object is an
abstraction of a set of real-world things (for example, an object may be
created around "date") The object would contain all information and


                                                                            34
functionality for that thing (A date
object it may contain labels like January, February, Tuesday, Wednesday. It
may contain functionality that manages leap years, determines if it is a
business day or a holiday, etc., See Fig. 1). Ideally, information about a
particular thing should reside in only one place in a system. The information
within an object is encapsulated (or hidden) from the rest of the system.
A system is composed of multiple objects (i.e., date function, reports, order
processing, etc., See Fig 2). When one object needs information from another
object, a request is sent asking for specific information. (for example, a report
object may need to know what today‘s date is and will send a request to the
date object) These requests are called messages and each object has an
interface that manages messages.
OO programming languages include features such as "class", "instance",
"inheritance", and "polymorphism" that increase the power and flexibility of
an object.

24. What is the use of friend function?

Friend functions
Sometimes a function is best shared among a number of different classes.
Such functions can be declared either as member functions of one class or as
global functions. In either case they can be set to be friends of other classes,
by using a friend specifier in the class that is admitting them. Such functions
can use all attributes of the class whichnames them as a friend, as if they
were themselves members of that class.
A friend declaration is essentially a prototype for a member function, but
instead of requiring an implementation with the name of that class attached
by the double colon syntax, a global function or member function of another
class provides the match.

class mylinkage
{
private:
mylinkage * prev;
mylinkage * next;

protected:
friend void set_prev(mylinkage* L, mylinkage* N);
void set_next(mylinkage* L);

public:
mylinkage * succ();
mylinkage * pred();
mylinkage();
};

void mylinkage::set_next(mylinkage* L) { next = L; }

void set_prev(mylinkage * L, mylinkage * N ) { N->prev = L; }

Friends in other classes


                                                                              35
It is possible to specify a member function of another class as a friend as
follows:

class C
{
friend int B::f1();
};
class B
{
int f1();
};

It is also possible to specify all the functions in another class as friends, by
specifying the entire class as a friend.

class A
{
friend class B;
};

Friend functions allow binary operators to be defined which combine private
data in a pair of objects. This is particularly powerful when using the operator
overloading features of C++. We will return to it when we look at overloading.

25. What are the differences between public, private, protected, static,
transient, final and volatile?
element Class Interface
Data field Method Constructor
modifier top level nested top level nested
(outer) (inner) (outer) (inner)
final yes yes no yes yes no no
private yes yes yes no yes no yes
protected yes yes yes no yes no yes
public yes yes yes yes yes yes yes
static yes yes no no yes no yes
transient yes no no no no no no
volatile yes no no no no no no

26. What are the different types of errors in php?

Three are three types of errors:

1. Notices: These are trivial, non-critical errors that PHP encounters while
executing a script - for example, accessing a variable that has not yet been
defined. By default, such errors are not displayed to the user at all - although,
as you will see, you can change this default behaviour.

2. Warnings: These are more serious errors - for example, attempting to
include() a file which does not exist. By default, these errors are displayed to
the user, but they do not result in script termination.




                                                                                   36
3. Fatal errors: These are critical errors - for example, instantiating an object
of a non-existent class, or calling a non-existent function. These errors cause
the immediate termination of the script, and PHP's default behaviour is to
display them to the user when they take place.

27. What is the functionality of the function strstr and stristr?

strstr() returns part of a given string from the first occurrence of a given
substring to the end of the string. For example:
strstr("user@example.com","@") will return "@example.com".
stristr() is idential to strstr() except that it is case insensitive.

28. What are the differences between PHP 3 and PHP 4 and PHP 5?

Go read the release notes at   http://php.net.

29. How can we convert asp pages to php pages?

You can download asp2php front-end application from the site
http://asp2php.naken.cc.

30. What is the functionality of the function htmlentities? Answer: htmlentities
— Convert all applicable characters to HTML entities
This function is identical to htmlspecialchars() in all ways, except with
htmlentities(), all characters which have HTML character entity equivalents
are translated into these entities.

31. How can we get second of the current time using date function?

$second = date("s");

32. How can we convert the time zones using php?

33. What is meant by urlencode and urldocode?

urlencode() returns the URL encoded version of the given string. URL coding
converts special characters into % signs followed by two hex digits. For
example: urlencode("10.00%") will return "10%2E00%25?. URL encoded
strings are safe to be used as part of URLs.
urldecode() returns the URL decoded version of the given string.

34. What is the difference between the functions unlink and unset?

unlink() deletes the given file from the file system.
unset() makes a variable undefined.

35. How can we register the variables into a session?

We can use the session_register ($ur_session_var) function.


                                                                               37
36. How can we get the properties (size, type, width, height) of an image
using php image functions?

To   know   the   Image type use exif_imagetype () function
To   know   the   Image size use getimagesize () function
To   know   the   image width use imagesx () function
To   know   the   image height use imagesy() function

37. How can we get the browser properties using php?

38. What is the maximum size of a file that can be uploaded using php and
how can we change this?

You can change maximum size of a file set upload_max_filesize variable in
php.ini file

39. How can we increase the execution time of a php script?

Set max_execution_time variable in php.ini file to your desired time in
second.

40. How can we take a backup of a mysql table and how can we restore it.?
Answer: Create a full backup of your database: shell> mysqldump –
tab=/path/to/some/dir –opt db_name Or: shell> mysqlhotcopy db_name
/path/to/some/dir
The full backup file is just a set of SQL statements, so restoring it is very
easy:

shell> mysql "."Executed";
mysql_close($link2);

53. List out the predefined classes in php?

Directory
stdClass
__PHP_Incomplete_Class
exception
php_user_filter

54. How can I make a script that can be bilanguage (supports Eglish,
German)?

You can change charset variable in above line in the script to support
bilanguage.

55. What are the difference between abstract class and interface?

Abstract class: abstract classes are the class where one or more methods are
abstract but not necessarily all method has to be abstract. Abstract methods
are the methods, which are declare in its class but not define. The definition
of those methods must be in its extending class.

                                                                                38
Interface: Interfaces are one type of class where all the methods are abstract.
That means all the methods only declared but not defined. All the methods
must be define by its implemented class.

56. How can we send mail-using JavaScript?

NO! JavaScript can't email a form! but, there are alternatives to send the
form data to an email address.

57. How can we repair a mysql table?

The syntex for repairing a mysql table is
REPAIR TABLENAME, [TABLENAME, ], [Quick],[Extended]
This command will repair the table specified if the quick is given the mysql
will do a repair of only the index tree if the extended is given it will create
index row by row

58. What are the advantages of stored procedures, triggers, indexes?

A stored procedure is a set of SQL commands that can be compiled and
stored in the server. Once this has been done, clients don't need to keep re-
issuing the entire query but can refer to the stored procedure. This provides
better overall performance because the query has to be parsed only once,
and less information needs to be sent between the server and the client. You
can also raise the conceptual level by having libraries of functions in the
server. However, stored procedures of course do increase the load on the
database server system, as more of the work is done on the server side and
less on the client (application) side.
Triggers will also be implemented. A trigger is effectively a type of stored
procedure, one that is invoked when a particular event occurs. For example,
you can install a stored procedure that is triggered each time a record is
deleted from a transaction table and that stored procedure automatically
deletes the corresponding customer from a customer table when all his
transactions are deleted.
Indexes are used to find rows with specific column values quickly. Without an
index, MySQL must begin with the first row and then read through the entire
table to find the relevant rows. The larger the table, the more this costs. If
the table has an index for the columns in question, MySQL can quickly
determine the position to seek to in the middle of the data file without having
to look at all the data. If a table has 1,000 rows, this is at least 100 times
faster than reading sequentially. If you need to access most of the rows, it is
faster to read sequentially, because this minimizes disk seeks.

59. What is the maximum length of a table name, database name, and
fieldname in mysql?

Database name- 64
Table name -64
Fieldname-64

60. How many values can the SET function of mysql takes?


                                                                                  39
Mysql set can take zero or more values but at the maximum it can take 64
values

61. What are the other commands to know the structure of table using mysql
commands except explain command?

describe table_name;

62. How many tables will create when we create table, what are they?

3 tables will create when we create table. They are
The '.frm' file stores the table definition.
The data file has a '.MYD' (MYData) extension.
The index file has a '.MYI' (MYIndex) extension,

63. What is the purpose of the following files having extensions 1) frm 2) MYD
3) MYI. What these files contains?

In MySql, the default table type is MyISAM.
Each MyISAM table is stored on disk in three files. The files have names that
begin with the table name and have an extension to indicate the file type.
The '.frm' file stores the table definition.
The data file has a '.MYD' (MYData) extension.
The index file has a '.MYI' (MYIndex) extension,

64. What is maximum size of a database in mysql?

If the operating system or filesystem places a limit on the number of files in a
directory, MySQL is bound by that constraint.
The efficiency of the operating system in handling large numbers of files in a
directory can place a practical limit on the number of tables in a database. If
the time required to open a file in the directory increases significantly as the
number of files increases, database performance can be adversely affected.
The amount of available disk space limits the number of tables.
MySQL 3.22 had a 4GB (4 gigabyte) limit on table size. With the MyISAM
storage engine in MySQL 3.23, the maximum table size was increased to
65536 terabytes (2567 – 1 bytes). With this larger allowed table size, the
maximum effective table size for MySQL databases is usually determined by
operating system constraints on file sizes, not by MySQL internal limits.
The InnoDB storage engine maintains InnoDB tables within a tablespace that
can be created from several files. This allows a table to exceed the maximum
individual file size. The tablespace can include raw disk partitions, which
allows extremely large tables. The maximum tablespace size is 64TB.
The following table lists some examples of operating system file-size limits.
This is only a rough guide and is not intended to be definitive. For the most
up-to-date information, be sure to check the documentation specific to your
operating system.
Operating System File-size Limit
Linux 2.2-Intel 32-bit 2GB (LFS: 4GB)
Linux 2.4+ (using ext3 filesystem) 4TB
Solaris 9/10 16TB
NetWare w/NSS filesystem 8TB

                                                                              40
Win32 w/ FAT/FAT32 2GB/4GB
Win32 w/ NTFS 2TB (possibly larger)
MacOS X w/ HFS+ 2TB

65. Give the syntax of Grant and Revoke commands?
The generic syntax for grant is as following
> GRANT [rights] on [database/s] TO [username@hostname] IDENTIFIED BY
[password]
now rights can be
a) All privileges
b) combination of create, drop, select, insert, update and delete etc.

We can grant rights on all databse by using *.* or some specific database by
database.* or a specific table by database.table_name
username@hotsname can be either username@localhost,
username@hostname and username@%
where hostname is any valid hostname and % represents any name, the *.*
any condition
password is simply the password of user

The generic syntax for revoke is as following
> REVOKE [rights] on [database/s] FROM [username@hostname]
now rights can be as explained above
a) All privileges
b) combination of create, drop, select, insert, update and delete etc.
username@hotsname can be either username@localhost,
username@hostname and username@%
where hostname is any valid hostname and % represents any name, the *.*
any condition

66. Explain Normalization concept?

The normalization process involves getting our data to conform to three
progressive normal forms, and a higher level of normalization cannot be
achieved until the previous levels have been achieved (there are actually five
normal forms, but the last two are mainly academic and will not be
discussed).

First Normal Form

The First Normal Form (or 1NF) involves removal of redundant data from
horizontal rows. We want to ensure that there is no duplication of data in a
given row, and that every column stores the least amount of information
possible (making the field atomic).

Second Normal Form

Where the First Normal Form deals with redundancy of data across a
horizontal row, Second Normal Form (or 2NF) deals with redundancy of data
in vertical columns. As stated earlier, the normal forms are progressive, so to


                                                                               41
achieve Second Normal Form, your tables must already be in First Normal
Form.

Third Normal Form

I have a confession to make; I do not often use Third Normal Form. In Third
Normal Form we are looking for data in our tables that is not fully dependant
on the primary key, but dependant on another value in the table

67. How can we find the number of rows in a table using mysql?

Answer: Use this for mysql
>SELECT COUNT(*) FROM table_name;
but if u r particular about no of rows with some special result
do this
>SELECT [colms],COUNT(*) FROM table_name [where u put conditions];

68. How can we find the number of rows in a result set using php?

Answer: for PHP

$result = mysql_query($any_valid_sql, $database_link);
$num_rows = mysql_num_rows($result);
echo "$num_rows rows found";

69. How many ways we can we find the current date using mysql?

SELECT CURDATE();
CURRENT_DATE() = CURDATE()
for time use
SELECT CURTIME();
CURRENT_TIME() = CURTIME()

70. What are the advantages and disadvantages of CASCADE STYLE SHEETS?

External Style Sheets

Advantages

Can control styles for multiple documents at once
Classes can be created for use on multiple HTML element types in many
documents
Selector and grouping methods can be used to apply styles under complex
contexts

Disadvantages

An extra download is required to import style information for each document
The rendering of the document may be delayed until the external style sheet
is loaded
Becomes slightly unwieldy for small quantities of style definitions

                                                                            42
Embedded Style Sheets

Advantages

Classes can be created for use on multiple tag types in the document
Selector and grouping methods can be used to apply styles under complex
contexts
No additional downloads necessary to receive style information

Disadvantages

This method can not control styles for multiple documents at once

Inline Styles

Advantages

Useful for small quantities of style definitions
Can override other style specification methods at the local level so only
exceptions need to be listed in conjunction with other style methods

Disadvantages

Does not distance style information from content (a main goal of SGML/HTML)
Can not control styles for multiple documents at once
Author can not create or control classes of elements to control multiple
element types within the document
Selector grouping methods can not be used to create complex element
addressing scenarios

71. What type of inheritance that php supports? Answer: In PHP an extended
class is always dependent on a single base class, that is, multiple inheritance
is not supported. Classes are extended using the keyword 'extends'.

72. How can increase the performance of mysql select query?

The structure of table view buyers is as follows
+—————-+————-+——+—–+———+—————-+
| Field | Type | Null | Key | Default | Extra |
+—————-+————-+——+—–+———+—————-+
| user_pri_id | int(15) | | PRI | NULL | auto_increment |
| userid | varchar(10) | YES | | NULL | |
+—————-+————-+——+—–+———+—————-+
the value of user_pri_id the last row 2345 then What will happen in
the following conditions

Condition1: Delete all the rows and insert another row then What is the
starting value for this auto incremented field user_pri_id ,
Condition2: Delete the last row(having the field value 2345) and insert
another row then What is the value for this auto incremented field user_pri_id


                                                                             43
In general, when you want to make a slow SELECT … WHERE query faster,
the first thing to check is whether you can add an index. All references
between different tables should usually be done with indexes. You can use the
EXPLAIN statement to determine which indexes are used for a SELECT. See
section 7.4.5 How MySQL Uses Indexes and section 7.2.1 EXPLAIN Syntax
(Get Information About a SELECT).
Some general tips for speeding up queries on MyISAM tables:

To help MySQL optimize queries better, use ANALYZE TABLE or run
myisamchk –analyze on a table after it has been loaded with data. This
updates a value for each index part that indicates the average number of
rows that have the same value. (For unique indexes, this is always 1.) MySQL
will use this to decide which index to choose when you join two tables based
on a non-constant expression. You can check the result from the table
analysis by using SHOW INDEX FROM tbl_name and examining the Cardinality
value. myisamchk –description –verbose shows index distribution information.

To sort an index and data according to an index, use myisamchk –sort-index
–sort-records=1 (if you want to sort on index 1). This is a good way to make
queries faster if you have a unique index from which you want to read all
records in order according to the index. Note that the first time you sort a
large table this way, it may take a long time.

In both cases let the value for auto increment field be n then next row will
have value n+1 i.e. 2346

73. What are the advantages/disadvantages of mysql and php?

Both of them are open source software (so free of cost), support cross
platform. php is faster then ASP and JSP.

74. What is the difference between GROUP BY and ORDER BY in Sql?

To sort a result, use an ORDER BY clause.

The most general way to satisfy a GROUP BY clause is to scan the whole table
and create a new temporary table where all rows from each group are
consecutive, and then use this temporary table to discover groups and apply
aggregate functions (if any).
ORDER BY [col1],[col2],…,[coln]; Tels DBMS according to what columns it
should sort the result. If two rows will hawe the same value in col1 it will try
to sort them according to col2 and so on.
GROUP BY [col1],[col2],…,[coln]; Tels DBMS to group results with same value
of column col1. You can use COUNT(col1), SUM(col1), AVG(col1) with it, if
you want to count all items in group, sum all values or view average

75. What is the difference between char and varchar data types?

char(M) M bytes 0

80. How can we change the name of a column of a table?

                                                                               44
MySQL query to rename table: RENAME TABLE tbl_name TO new_tbl_name
[, tbl_name2 TO new_tbl_name2] …
or,
ALTER TABLE tableName CHANGE OldName newName.

81. How can we change the name and data type of a column of a table?

ALTER [IGNORE] TABLE tbl_name
alter_specification [, alter_specification] | CHANGE [COLUMN] old_col_name
column_definition
[FIRST|AFTER col_name]

82. What are the differences between drop a table and truncate a table?
Answer: Delete a Table or DatabaseTo delete a table (the table structure,
attributes, and indexes will also be deleted).
What if we only want to get rid of the data inside a table, and not the table
itself? Use the TRUNCATE TABLE command (deletes only the data inside the
table).

83. When you want to show some part of a text displayed on an HTML page in
red font color, what different possibilities are there to do this? What are the
advantages/disadvantages of these methods?

Using Html font color tag:
I am Amin
Using tag in CSS:
STRONG {color:red}
So when we use the tag:
I am Amin about this.
Using Class in CSS:

.colorclass
{
color:#FF3399;
font-weight:900;
}

I am Amin
If we use html the modification will be trouble some because we have to
change the code of the page. But when we use CSS then it will be easy to
change the CSS file and we can get the desired out put.

84. When viewing an HTML page in a Browser, the Browser often keeps this
page in its cache. What can be possible advantages/disadvantages of page
caching? How can you prevent caching of a certain page (please give several
alternate solutions)?

When you use the metatag in the header section at the beginning of an HTML
Web page, the Web page may still be cached in the Temporary Internet Files
folder.



                                                                                45
A page that Internet Explorer is browsing is not cached until half of the 64 KB
buffer is filled. Usually, metatags are inserted in the header section of an
HTML document, which appears at the beginning of the document. When the
HTML code is parsed, it is read from top to bottom. When the metatag is
read, Internet Explorer looks for the existence of the page in cache at that
exact moment. If it is there, it is removed. To properly prevent the Web page
from appearing in the cache, place another header section at the end of the
HTML ocument. For example:

85. What are the different methods of passing data or information between
two calls of a web page? What are the advantages/disadvantages of these
methods?

86. An Apache web server is running on a Linux system. Suddenly, the web
server delivers the pages very slow. How could you find out possible reasons
for that (when using system commands, please specify their names)?

87. What are the different ways to login to a remote server? Explain the
means, advantages and disadvantages?

There is at least 3 ways to logon to a remote server:
Use ssh or telnet if you concern with security
You can also use rlogin to logon to a remote server.

88. Please give a regular _expression (preferably Perl/PREG style), which can
be used to identify the URL from within a HTML link tag. Example: The regular
_expression should match the tag mysqldump -u user -ppassword –opt -full
database_name > backupfile.sql
Then move the resulting file(s) to your preferred backup areas. If you require
more information on the mysqldump command, then simply check out this
URL:www.mysql.com/documentation/mysql
Copy all the relevant table files.

If the server isn't updating anything (or you've deliberately killed mysqld for
this purpose) then you can copy all the files with the following extensions in
your MySQL data directory:
*.frm
*.myd
*.myi
Make sure you restart the MySQL daemon once you finish copying and
downloading the files to your preferred backup areas.
TIP: once you've completed the backup, restart MySQL with the –log-update
switch. This will allow you to keep track of all modifications done in the
MySQL tables since your last 'dump'.
To restore your dumps, you should either restore to an existing database or
create a new database using
shell> mysqladmin create database_name
then issue the following command :
shell> mysql -u user -ppassword database_name

94. What is meant by MIME?


                                                                              46
Multipurpose Internet Mail Extensions.
WWW's ability to recognise and handle files of different types is largely
dependent on the use of the MIME (Multipurpose Internet Mail Extensions)
standard. The standard provides for a system of registration of file types with
information about the applications needed to process them. This information
is incorporated into Web server and browser software, and enables the
automatic recognition and display of registered file types. …

95. What is meant by PEAR in php?

PEAR is short for "PHP Extension and Application Repository" and is
pronounced just like the fruit. The purpose of PEAR is to provide:
A structured library of open-sourced code for PHP users
A system for code distribution and package maintenance
A standard style for code written in PHP
The PHP Foundation Classes (PFC),
The PHP Extension Community Library (PECL),
A web site, mailing lists and download mirrors to support the PHP/PEAR
community
PEAR is a community-driven project with the PEAR Group as the governing
body. The project has been founded by Stig S. Bakken in 1999 and quite a lot
of people have joined the project since then.
http://pear.php.net/manual/en/introduction.php

96. How can I use the COM components in php?

The COM class provides a framework to integrate (D)COM components into
your PHP scripts.
string COM::COM ( string module_name [, string server_name [, int
codepage]])
COM class constructor. Parameters:
module_name
name or class-id of the requested component.
server_name
name of the DCOM server from which the component should be fetched. If
NULL, localhost is assumed. To allow DCOM com.allow_dcom has to be set to
TRUE in php.ini.
codepage
specifies the codepage that is used to convert php-strings to unicode-strings
and vice versa. Possible values are CP_ACP, CP_MACCP, CP_OEMCP,
CP_SYMBOL, CP_THREAD_ACP, CP_UTF7 and CP_UTF8.
Usage:
Version}\n"; //bring it to front $word->Visible = 1; //open an empty
document $word->Documents->Add(); //do some weird stuff $word-
>Selection->TypeText("This is a test…"); $word->Documents[1]-
>SaveAs("Useless test.doc"); //closing word $word->Quit(); //free the object
$word->Release(); $word = null; ?>

97. How can I load the dlla€™s dynamically?

98. How many ways we can give the output to a browser?


                                                                             47
HTML output
PHP, ASP, JSP, Servlet Function
Script Language output Function
Different Type of embedded Package to output to a browser

99. How can we know that a session is started or not?

a session starts by session_start()function.
this session_start() is always declared in header portion.it always declares
first.then we write session_register().

100. What is the default session time in php and how can I change it?

The default session time in php is until closing of browser

101. What changes I have to done in php.ini file for file uploading?

Make the following Line uncomment like:
; Whether to allow HTTP file uploads.
file_uploads = On
; Temporary directory for HTTP uploaded files (will use system default if not
; specified).
upload_tmp_dir = C:\apache2triad\temp
; Maximum allowed size for uploaded files.
upload_max_filesize = 2M

102. What are the differences between mysql_fetch_array(),
mysql_fetch_object(), mysql_fetch_row()?

mysql_fetch_array — Fetch a result row as an associative array, a numeric
array, or both.
mysql_fetch_object ( resource result )
Returns an object with properties that correspond to the fetched row and
moves the internal data pointer ahead. Returns an object with properties that
correspond to the fetched row, or FALSE if there are no more rows
mysql_fetch_row() fetches one row of data from the result associated with
the specified result identifier. The row is returned as an array. Each result
column is stored in an array offset, starting at offset 0.

103. How can I set a cron and how can I execute it in Unix, Linux, and
windows?

Cron is very simply a Linux module that allows you to run commands at
predetermined times or intervals. In Windows, it‘s called Scheduled Tasks.
The name Cron is in fact derived from the same word from which we get the
word chronology, which means order of time.
The easiest way to use crontab is via the crontab command.
# crontab –e
This command ‗edits‘ the crontab. Upon employing this command, you will be
able to enter the commands that you wish to run. My version of Linux uses
the text editor vi. You can find information on using vi here.


                                                                                48
The syntax of this file is very important – if you get it wrong, your crontab will
not function properly. The syntax of the file should be as follows:
minutes hours day_of_month month day_of_week command
All the variables, with the exception of the command itself, are numerical
constants. In addition to an asterisk (*), which is a wildcard that allows any
value, the ranges permitted for each field are as follows:
Minutes: 0-59
Hours: 0-23
Day_of_month: 1-31
Month: 1-12
Weekday: 0-6
We can also include multiple values for each entry, simply by separating each
value with a comma.
command can be any shell command and, as we will see momentarily, can
also be used to execute a Web document such as a PHP file.
So, if we want to run a script every Tuesday morning at 8:15 AM, our
mycronjob file will contain the following content on a single line:
15 8 * * 2 /path/to/scriptname
This all seems simple enough, right? Not so fast! If you try to run a PHP script
in this manner, nothing will happen (barring very special configurations that
have PHP compiled as an executable, as opposed to an Apache module). The
reason is that, in order for PHP to be parsed, it needs to be passed through
Apache. In other words, the page needs to be called via a browser or other
means of retrieving Web content.
For our purposes, I‘ll assume that your server configuration includes wget, as
is the case with most default configurations. To test your configuration, log in
to shell. If you‘re using an RPM-based system (e.g. Redhat or Mandrake),
type the following:
# wget –help
If you are greeted with a wget package identification, it is installed in your
system.
You could execute the PHP by invoking wget on the URL to the page, like so:
# wget http://www.example.com/file.php
Now, let‘s go back to the mailstock.php file we created in the first part of this
article. We saved it in our document root, so it should be accessible via the
Internet. Remember that we wanted it to run at 4PM Eastern time, and send
you your precious closing bell report? Since I‘m located in the Eastern
timezone, we can go ahead and set up our crontab to use 4:00, but if you live
elsewhere, you might have to compensate for the time difference when
setting this value.
This is what my crontab will look like:
0 4 * * 1,2,3,4,5 wget http://www.example.com/mailstock.php

104. Steps for the payment gateway processing?

An online payment gateway is the interface between your merchant account
and your Web site. The online payment gateway allows you to immediately
verify credit card transactions and authorize funds on a customer‘s credit card
directly from your Web site. It then passes the transaction off to your
merchant bank for processing, commonly referred to as transaction batching

105. How many ways I can register the variables into session?

                                                                               49
session_register(); $_SESSION[]; $HTTP_SESSION_VARS[];

106. Explain different types of errors in php (i.e. arguments in error reporting
function)?

Three are three types of errors:

1. Notices: These are trivial, non-critical errors that PHP encounters while
executing a script - for example, accessing a variable that has not yet been
defined. By default, such errors are not displayed to the user at all - although,
as you will see, you can change this default behaviour.

2. Warnings: These are more serious errors - for example, attempting to
include() a file which does not exist. By default, these errors are displayed to
the user, but they do not result in script termination.

3. Fatal errors: These are critical errors - for example, instantiating an object
of a non-existent class, or calling a non-existent function. These errors cause
the immediate termination of the script, and PHP's default behaviour is to
display them to the user when they take place.

107. How many ways I can redirect a php page?

Here are the possible ways of php page redirection.
Using Java script:
'; echo 'window.location.href="'.$filename.'";'; echo ''; echo ''; echo ''; echo
''; } } redirect('http://maosjb.com'); ?>
Using php function:
Header("Location:http://maosjb.com ");

108. List out different arguments in php header function?

void header ( string string [, bool replace [, int http_response_code]])

109. What type of headers have to add in the mail function in which file a
attached?


$boundary = '—–=' . md5( uniqid ( rand() ) );
$headers = "From: \"Me\"\n";
$headers .= "MIME-Version: 1.0\n";
$headers .= "Content-Type: multipart/mixed; boundary=\"$boundary\"";

110. What is the difference between and And which can be preferable?

move_uploaded_file ( string filename, string destination)

This function checks to ensure that the file designated by filename is a valid
upload file (meaning that it was uploaded via PHP's HTTP POST upload
mechanism). If the file is valid, it will be moved to the filename given by
destination.

                                                                                   50
If filename is not a valid upload file, then no action will occur, and
move_uploaded_file() will return FALSE.

If filename is a valid upload file, but cannot be moved for some reason, no
action will occur, and move_uploaded_file() will return FALSE. Additionally, a
warning will be issued.

116. What is the difference between Reply-to and Return-path in the headers
of a mail function?

Reply-to: Reply-to is where to delivery the reply of the mail.

Return-path: Return path is when there is a mail delivery failure occurs then
where to delivery the failure notification.

117. Explain about Type Juggling in php?

PHP does not require (or support) explicit type definition in variable
declaration; a variable's type is determined by the context in which that
variable is used. That is to say, if you assign a string value to variable $var,
$var becomes a string. If you then assign an integer value to $var, it
becomes an integer.
An example of PHP's automatic type conversion is the addition operator '+'. If
any of the operands is a float, then all operands are evaluated as floats, and
the result will be a float. Otherwise, the operands will be interpreted as
integers, and the result will also be an integer. Note that this does NOT
change the types of the operands themselves; the only change is in how the
operands are evaluated.


$foo   += 2; // $foo is now an integer (2)
$foo   = $foo + 1.3; // $foo is now a float (3.3)
$foo   = 5 + "10 Little Piggies"; // $foo is integer (15)
$foo   = 5 + "10 Small Pigs"; // $foo is integer (15)

If the last two examples above seem odd, see String conversion to numbers.
If you wish to change the type of a variable, see settype().
If you would like to test any of the examples in this section, you can use the
var_dump() function.
Note: The behavior of an automatic conversion to array is currently
undefined.

Since PHP (for historical reasons) supports indexing into strings via offsets
using the same syntax as array indexing, the example above leads to a
problem: should $a become an array with its first element being "f", or should
"f" become the first character of the string $a?
The current versions of PHP interpret the second assignment as a string offset
identification, so $a becomes "f", the result of this automatic conversion
however should be considered undefined. PHP 4 introduced the new curly
bracket syntax to access characters in string, use this syntax instead of the
one presented above:


                                                                              51
118. How can I get the only name of the current executing file?

119. How can I embed a java programme in php file and what changeshave
to be done in php.ini file?

There are two possible ways to bridge PHP and Java: you can either integrate
PHP into a Java Servlet environment, which is the more stable and efficient
solution, or integrate Java support into PHP. The former is provided by a SAPI
module that interfaces with the Servlet server, the latter by this Java
extension.
The Java extension provides a simple and effective means for creating and
invoking methods on Java objects from PHP. The JVM is created using JNI,
and everything runs in-process.

Example Code:

getProperty('java.version') . ''; echo 'Java vendor=' . $system-
>getProperty('java.vendor') . ''; echo 'OS=' . $system-
>getProperty('os.name') . ' ' . $system->getProperty('os.version') . ' on ' .
$system->getProperty('os.arch') . ' '; // java.util.Date example $formatter =
new Java('java.text.SimpleDateFormat', "EEEE, MMMM dd, yyyy 'at' h:mm:ss
a zzzz"); echo $formatter->format(new Java('java.util.Date')); ?>

The behaviour of these functions is affected by settings in php.ini.
Table 1. Java configuration options
Name
Default
Changeable
java.class.path
NULL
PHP_INI_ALL
Name Default Changeable
java.home
NULL
PHP_INI_ALL
java.library.path
NULL
PHP_INI_ALL
java.library
JAVALIB
PHP_INI_ALL

120. How can I find what type of images that the php version supports?

Using Imagetypes() function we can know
Usage:

121. The table tbl_sites contains the following data.
—————————————————–
Userid sitename country
——————————————————
1 sureshbabu indian

                                                                            52
   2 phpprogrammer andhra
   3 php.net usa
   4 phptalk.com germany
   5 mysql.com usa
   6 sureshbabu canada
   7 phpbuddy.com pakistan
   8. phptalk.com austria
   9. phpfreaks.com sourthafrica
   10. phpsupport.net russia
   11. sureshbabu australia
   12. sureshbabu nepal
   13. phptalk.com italy

   Write a select query that will displayed the duplicated site name and how
   many times it is duplicated?

   SELECT sitename,
   COUNT(sitename) AS NumOccurrences
   FROM tbl_sites
   GROUP BY sitemail
   HAVING ( COUNT(sitemail) > 1 )
   Or
   SELECT sitename
   FROM tbl_sites
   GROUP BY sitename
   HAVING ( COUNT(sitename) = 1 )

   122. How can we send mail using JavaScript?

   No. You can't send mail using Javascript. But you can execute a client side
   email client to send the email using mailto: code.
   Using clientside email client

   function myfunction(form)
   {
   tdata=document.myform.tbox1.value;
   location="mailto:mailid@domain.com?subject="+tdata+"/MYFORM";
   return true; }
   }

83.Tejas vadalia said,

   Answer For Q.6 can be found at
   http://www.phpbuilder.com/manual/en/language.variables.varia
   ble.php

84.hita said,

   Answer for Q.No:7

   echo strstr(‖info@abc.com‖,‖abc‖);

                                                                                 53
85.hita said,

   Answer of Q.No:48

   count(array) or sizeof(array)

86.Sajeesh Francis said,

   Answer for Q.No:7

   $data = ―http://info@abc.com‖;
   $pattern = ―/[A-Z0-9.-]+\.[A-Z]{2,4}\b/i‖;

   if(preg_match($pattern, $data, $matches)){
   echo $matches[0];
   } else {
   echo ―A match was not found.‖;
   }

87.Rahul Chahwala said,

   25. What are the differences between public, private, protected, static,
   transient, final and volatile?

   Public: Public declared items can be accessed everywhere.
   Protected: Protected limits access to inherited and parent classes (and to the
   class that defines the item).
   Private: Private limits visibility only to the class that defines the item.
   Static: A static variable exists only in a local function scope, but it does not
   lose its value when program execution leaves this scope.
   Final: Final keyword prevents child classes from overriding a method by
   prefixing the definition with final. If the class itself is being defined final then
   it cannot be extended.

88.Rahul Chahwala said,

   Answer to que 7

   Use the strrchr function.
   strrchr(‖http://info@abc.com‖, ―a‖ )
   //output
   abc.com

89.Rahul Chahwala said,

   Answer to question 16

   nl2br():Inserts HTML line breaks lines in a string.
   Example:
   echo (‖What a nice \n day‖);


                                                                                      54
   //output
   What a nice day.

   echo nl2br(‖What a nice \n day‖);
   //output
   What a nice
   day

90.Arghadip Acharya said,

   Answer of Question Number 1:

   This is not the only answer between GET & POST method posted by
   Mr.Cahndu.
   Ther are another differences:
   Using GET method, only 255 datas can be submitted (For some browser it
   exceeds to 4kb), but, POST method has no such restriction.
   GET method is used for the creation of search engines, where inserion or
   modification of data is not required. This is good practice of codeing.
   POST method is used when the insertion or modification of data in database is
   required.

   Thank You.

91.nilanjan karmakar said,

   function test()
   {
   alert(‖abc‖);
   document.form1.action=‘test1.php‘;
   document.form1.submit();
   }

92.nilanjan karmakar (question:8) said,

   CREATE TABLE `test` (
   `id` INT( 10 ) NOT NULL ,
   `ss` VARCHAR( 122 ) NOT NULL ,
   `sa` VARCHAR( 122 ) NOT NULL
   );

93.shiva.G said,

   How can we swap two varaibles without using any intermediate variable?

94.Kiran said,

   Correction for the 11 the Question of PHP interview questions
   ————————————————————-
   # If the variable $a is equal to 5 and variable $b is equal to character a,


                                                                                 55
   what‘s the value of $$b? -
   100, it‘s a reference to existing variable.

   Correction
   ———-
   $$b=$a Where as the value of $a=5;
   so the Actual answer is 5.

95.appsaheb bagali said,

   Q no 1)

   1. GET method have limination to transper the data as compare to POST
   2. GET method data will show in the URL POST method data will pass through
   Header Body
   3. In file uplaod you must use the POST Method GET will not work
   4. In Search engine yahoo Google will use the GET methods because GET
   Method data
   will store in server logs of Apache. from they can keep track of the
   Frequentlly searched data

96.Romi said,

   37. How can we get the browser properties using PHP?
   Ans: Use function get_browser to get all the properties of the browser.
   $browser = get_browser(null, true);
   print_r($browser);

97.Tanvir Ahmad said,

   Answer of Question no 21
   In PHP you can generate hashes using the md5() and sha1 functions. md5()
   returns a 128-bit hash (32 hexadecimal characters), whereas sha1() returns a
   160-bit hash (40 hexadecimal characters). For example:

   This code will output the following:

   Original string: PHP & Information Security
   MD5 hash: 88dd8f282721af2c704e238e7f338c41
   SHA-1 hash: b47210605096b9aa0129f88695e229ce309dd362

   –
   In MySQL you can generate hashes internally using the password(), md5(), or
   sha1 functions. password() is the function used for MySQL‘s own user
   authentication system. It returns a 16-byte string for MySQL versions prior to
   4.1, and a 41-byte string (based on a double SHA-1 hash) for versions 4.1
   and up. md5() is available from MySQL version 3.23.2 and sha1() was added
   later in 4.0.2.

   mysql> select PASSWORD( ‗PHP & Information Security‘ );


                                                                              56
98.Nilay Anand said,

   I do dislike questions that require one to have memorized functions and
   parameter orders. I always prefer people to prove what they know, rather
   than what they don‘t know.
   The all above question need one to memorized PHP in depth.

99.Rakesh Chandel said,

   what function is used to free the resultset in php?
   what is the difference in trim() and chop()?

100.      rishi said,

   answer:
   How can we swap two varaibles without using any intermediate variable?
   x and y are variables
   step 1: x=x+y
   step 2: y=x-y
   step 3: x=x-y

101.      Amol Bhavsar said,

   Answer for Question 3 :
   You can submit form without Submit Button in Two ways :
   (1).Using images
   (2).Using Javascript : You can submit form using Javascript by first defining
   first functions and calling them on some events like ―onClick‖,‖onBlur‖ etc.

102.      Amol Bhavsar ,Pune (PHP Developer) said,

   Answer to question 1 :
   Main differences between GET & POST methods are :
   -GET method is the default method for forms.
   -In the form posted with GET method , the passed variables and their values
   are shown in address bar.
   -Therefore ,GET method is useful to BookMark an URL.
   -But‘also there is limit on length of values of form elments passed.
   -GET method is not secure as navigated values are displayed in address bar.
   -Get method is not recommonded in applications where user information
   security is required.

   -POST method does not display any content in the address bar so,complete
   bookmarking is not possible as that of GET method .
   -With the POST method ,there is no limit on amount of data POSTED.
   -POST method is recommonded where ,there is issue of user-information
   security.
   -POST method is

103.      Niladri said,



                                                                                   57
  Any one tell me what is outer - joining in mysql?

104.     Niladri said,

  what is the difference between split() and explode() ?

105.     Niladri said,

  What is the utility of GD Library ?

106.     Hitu Patel said,

  49). What is the difference between ereg_replace() and eregi_replace()?

  eregi_replace — replace regular expression case insensitive
  ereg_replace — replace regular expression

107.     Hitu Patel said,

  (3) .How can we submit a form without a submit button?

  (1) we can use the document.form.submit() function of javascript for submit
  the form.

108.     Hitu Patel said,

  (16). nl2br — Inserts HTML line breaks before all newlines in a string

109.     Hitu Patel said,

  (20). You can use the AES functions to store data in an encrypted form by
  modifying your queries:

  INSERT INTO t VALUES (1,AES_ENCRYPT(‘text‘,'password‘));

  For Decriyption use AES_DECRYPT()

110.     Sumanta said,

  How can we extract string ‗abc.com ‗ from a string ‗http://info@abc.com‘
  using regular expression of PHP?

  Ans is: $url = http://info@abc.com;
  $domain = strstr($url, ‗@‘, 1);
  echo $domain;

  It will print abc.com.

111.     Sumanta said,


                                                                              58
  Sorry for last comment.
  The actual answer is following:–

  $url = http://info@abc.com;
  $domain = strstr($url, ‗a‘);
  echo $domain;

  It will print abc.com.

112.     Manokaran said,

  Difference between Session and Cookie in PHP ?

  Session variables are stored in Server system.

  Cookie variables are stored in Client system.




                                                   59

				
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