What Is PHP?

The full form of PHP is Hypertext PreProcessor and is a server-side scripting language. The PHP code can be combined with regular HTML tags and parsed on the server. The creator of PHP, Rasmus Lerdorf first displayed the language in the form of a Perl script . In 1997 it was adapted by Andi Gutmans and Zeev Suraski to use a C-written compiler. They completely reconstructed the original PHP into the web language that we know and use today.

Uses of PHP

It is used in the creation of dynamic web pages. Web developers like it because of its fast parsing and flexibility and versatility. PHP is a popular tool for managing a form's data after it is submitted and comes built in with many different interfaces and API's. It has database capability built into the language, the most common database being MySQL. Typically the PHP can connect to any SQL enabled database.

The Syntax of PHP is similar in structure to Perl and C where curly braces { } define blocks of code and semi-colons specify the end of a statement PHP is as easy to learn as Perl. It maintains all the traditional loops, if/else, and subroutines that are expected in a programming language. One difference between the two is that the code'?' is embedded in with the HTML; you could however, use a separate file. The PHP code is different from HTML code by use of the opening and closing tags. When it finds a PHP file, it tells the server to scan through for these tags, and execute the code in between them. The server recognizes a PHP enabled file by its extension, .php. These are essentially HTML files with PHP codes in them.

Getting Started

To start PHP requires a server with PHP installed and a simple ASCII text editor such as Notepad or VI, eMacs, Kate, etc. for a UNIX/Linux machine.

What are the problems faced by PHP?

It is case sensitive. For example if you name a variable $MyVar, you cannot call it as $myvar or $mYvAr. In case you forget to close your curly brackets, then it helps to indent lines inside the curly braces so that any missing braces can be spotted easily.

BETA is a pure object oriented programming language developed by Scandinavian School in System Development, Nordic Universities.

This was released after a series of enhancements of their first object oriented language SimulaI which was a simulation language. Soon it was generalized into Simula67 which had the object oriented framework, and worked on the concepts of class, sub-class, virtual functions etc. This was enhanced by another object oriented language Delta that worked for system description; this meant it could express predicate logic and state changes. This was a non-executable effort and thus did not qualify as a language. So it was decided to design a programming language Gamma that works as Delta but is executable.

Eventually, Gamma was never made, rather Beta was made. While Beta was being made, it was realized that Beta was much more powerful than what Gamma would be or ever could be. Beta is a programming language like C++.

Currently, BETA is available on UNIX workstations, on PowerPC Macintosh and on Intel-based PCs. BETA has an optimum balance between compile time checking and run time checking. The type cast checking is done at compile time, however, for the entire set of type check and type conversion to be done at compile time requires a lot of time and thus increases the complexity of a program. Thus, an optimum balance has been made.

BETA is a logical description of the language. It works on the concepts of class, sub-class, virtual functions etc. It also contains transient variables, ones whose scope is program execution, and persistent variables, those whose values are retained in the disk space and are available at the time of next execution.

BETA is a pure object oriented programming language developed by Scandinavian School in System Development, Nordic Universities.

This was released after a series of enhancements of their first object oriented language SimulaI which was a simulation language. Soon it was generalized into Simula67 which had the object oriented framework, and worked on the concepts of class, sub-class, virtual functions etc. This was enhanced by another object oriented language Delta that worked for system description; this meant it could express predicate logic and state changes. This was a non-executable effort and thus did not qualify as a language. So it was decided to design a programming language Gamma that works as Delta but is executable.

Eventually, Gamma was never made, rather Beta was made. While Beta was being made, it was realized that Beta was much more powerful than what Gamma would be or ever could be. Beta is a programming language like C++.

Currently, BETA is available on UNIX workstations, on PowerPC Macintosh and on Intel-based PCs. BETA has an optimum balance between compile time checking and run time checking. The type cast checking is done at compile time, however, for the entire set of type check and type conversion to be done at compile time requires a lot of time and thus increases the complexity of a program. Thus, an optimum balance has been made.

BETA is a logical description of the language. It works on the concepts of class, sub-class, virtual functions etc. It also contains transient variables, ones whose scope is program execution, and persistent variables, those whose values are retained in the disk space and are available at the time of next execution.