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Pascal Programming Language

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					Pascal Programming Language




Pascal programming language was created in late 1960s by a Swiss computer scientist Niklaus Wirth.
It is based on the ALGOL programming language and named after the French mathematician Blaise
Pascal. Initially, it was intended to teach computer programming because it encourages structured
programming and using data structures. This is how the famous "hello world" program looks like:

Program HelloWorld (Output);



begin



Writeln ('Hello, world!');



end.




Definitions for data types and structures are simple and clear. Language provides an orthogonal and
recursive approach to data structures. You can declare arrays of arrays (multidimensional arrays),
arrays of records, records containing arrays, file elements can be records, arrays, records containing
arrays of records, etc. Some examples:

Type




TDay = 1..31;



TMonth = 1..12;



SimpleArray = Array [1..1000] of Integer;



2D_Array = Array [1..1000, 0..3] of Real;
Friend = (Barbara, Alice, Rebecca, Laura);



DateType = Record



Day: TDay;



Month: TMonth;



Year: Integer;



end;



Var Birthday: Array [Friend] of DateType;



The first major milestone in Pascal history was Turbo Pascal. Based on the compiler written by
Anders Hejlsberg, the product was licensed to Borland, and integrated into an IDE. It was also
available on the CP/M platform, but the biggest success Borland achieved with Turbo Pascal for DOS.
Borland continued the tradition of successful Pascal compilers with Delphi. Delphi is a visual rapid
application development environment using Object Pascal as programming language. There is also
an open-source compiler available: Free Pascal. It is a 32 and 64-bit compiler for various processors
like Intel x86, Amd64, PowerPC, Sparc and ARM. Pascal is also used for development of embedded
systems. Compilers are available for microcontrollers like 8051, AVR and ARM.



In 1983 the language was standardized as IEC/ISO 7185. In 1990 an extended standard was created
as ISO/IEC 10206. The ISO Pascal is somehow limited because it lacks some features like strings and
units. The most known and used syntax is the Borland Turbo Pascal syntax which added necessary
features to fill the gaps in the ISO standard. There is also a derivative of Turbo Pascal known as
Object Pascal (used in Borland Delphi) which was designed for object oriented programming.



Today, Pascal is still popular in various areas but not that much it was decades ago. It was replaced
mainly with C which is available for almost any platform. Nevertheless, there is still a large
community that finds Pascal programming language an excellent choice. It is easy to learn and easy
to read. If you give your identifiers meaningful names you can read the program almost like a plain
English text. Therefore it is very easy to transfer any algorithm into program. In addition to this the
language is not case sensitive which is another step closer to English language.



There are endless debates and comparisons of Pascal and C programming languages. Some favor
Pascal, other like C. There is no winner. Both languages are used to describe an algorithm. It is up to
the programmer to choose his preferred language.

				
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posted:7/27/2011
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