The current stable version of PHP is PHP 5.4.11 on 17-01-2013 as still waiting for PHP6 with unicode handling thing in the latest version.
There are lot of difference among PHP3 , PHP4 and PHP5 version of php and PHP6 is till in under development process. So we are checking difference between oldest version and they have less functionality as compare to new one.
Following are the some points:
- PHP3 is oldest stable version and it was like C language which is pure procedural constructive.
- PHP4 have some OOP concept added like class and object with new functionality.
- PHP5 have approximately all major oops functionality been added along with below thing :
- Exceptions and exception handling implementation feature has been added.
- Type hinting and it allows you to force the type of a specific argument.
- Constructor and destructor functions has been added.
- autoload function for dynamically including some include files depending on the class which you are trying to create.
- Overloading of methods through the call function.
- Some functions are removed in PHP 5.x like ereg,ereg_replace,magic_quotes, session_register,split() etc