Docstoc

java lect 02

Document Sample
java lect 02 Powered By Docstoc
					                           Java
                  Tutotrial for [NLP-AI]
                             2

                   ashishfa@cse.iitb.ac.in




6 February 2011                              1
                                                     asgn1
                                                     asgn2

                  Last Assignment

          ? Print the details in tabular format
                      - use tabs \t

                               we print '\\' with
         System.out.println("\"Can
           System.out.println() statement?\"" );



6 February 2011        Java Tutorial series part 2       2
                     Storing data

In Java, Data can be stored as
        Numbers
         2, 6.67, 0.009
        Characters
         „c‟, „p‟, „?‟, „2‟
        Strings
         “data”, “Hindi language”, “$99”, “www.rediff.com”




6 February 2011          Java Tutorial series part 2         3
                                                               int1

                          Program                              int2




// this program will declare and print a number
class int2
{
        public static void main(String[] arguments)
        {
             int weight = 68;
             System.out.println("your weight is " + weight);
        }
}
//end of program



6 February 2011            Java Tutorial series part 2                4
           Comments(double slash)
   Not executed
   For documentation
   Can be placed on any line
   Anything written after // is not executed
   E.g.
        // this is a comment
   Used to explain/describe what is done in the
    program
   Good practice
6 February 2011         Java Tutorial series part 2   5
                                                    float1

                  Types of numbers

   int
     Whole numbers like 0, 575, -345 etc.


   double
     Numbers with decimal point
     like 12.453, 3.432, 0.0000002



6 February 2011       Java Tutorial series part 2            6
                  Variable declaration
   Before using any name, it must be declared
      (with its type i.e int or double).
   Needed only once in one program
   Generally, done initially
   Syntax
                            datatype name;
    double total; // stores the total value
    int index;
    int a,b , c, sum, interest;


6 February 2011              Java Tutorial series part 2   7
                                                     int3
                   Assignment                        int5




int a; //declaration – needed once
a = 10 ; // assignment … declared above

int a = 10; // assignment and declaration together
10 = a ; // not possible – compilation error
Left hand side is always a variable for assignment

                         Storage area
a          10



6 February 2011      Java Tutorial series part 2        8
                                                      int4

                  Assignment…

int a , b ;       //   a =? b = ?
  a = 4;          //   a=4 b=?
  b = 7;          //   a=4 b=7
  a = b;          //   a=7 b=7
  b = a;          //    a=7 b=7
  a = 5;          //    a=5 b=7

6 February 2011         Java Tutorial series part 2          9
                                                         char1

                      Character data                     char2




   Characters
       „a‟, „A‟, „c‟ , „?‟ , „3‟ , „ ‟
                       (last is the single space)

   Enclosed in single quotes
   Character variable declaration
       char ch;
   Character assignment
          ch = „k‟;

6 February 2011            Java Tutorial series part 2      10
                                                                           string1
                                                                           string2

                           String data                                     string3



   Strings are sequence of characters enclosed in double quotes
   Declaration
          String name;
          String address;
          String line;
   Assignment
          name = “ram”;
          line = “this is a line with spaces”;
          name = “a”; // single character can be stored
          name = “”; // empty string
   The sequence of characters enclosed in double quotes, printed in println()
    are also strings.
   E.g. System.out.println( “Welcome ! “ );




6 February 2011               Java Tutorial series part 2                        11
                      Practice problem
   Try to print these two figures on the screen using println and least number
    of strings
            *******
             *****
              ***
               *
              ***
             *****
            *******


          **********
          *        *
          *        *
          *        *
          **********




6 February 2011               Java Tutorial series part 2                     12
                  Thank you




6 February 2011    Java Tutorial series part 2   13

				
DOCUMENT INFO
Description: java and its various features
About if any file u wil find copyright contact me it will be remove in 3 to 4 buisnees days. add me on sanjaydudeja007@gmail.com or visit http://www.ohotech.com/