What are the Predefined Classes and Predefined Constants in PHP?

[Author]

Hi friends,
I have recently started with the PHP programming language, so I don't know much enough about the PHP. Before this I have done C++ and Core Java as programming language. I also have bit knowledge about the HTML and JavaScript. I really don't know the basic things about the PHP. I now want to know about the classes and constants that are defined previously. I thought that anyone would be interested in solving my doubt. So please tell me what are the Predefined Classes and Predefined Constants in PHP.??

[Allan.d]

For knowing the predefined classes you should know about the Standard Classes. These classes are defined in the standard class set of PHP included with all versions of PHP. Directory - The class that can instantiate dir are :

Directory ( 
string $ path; 
resource $ handle; 
string read (void) 
void rewind (void) 
void close (void) 
) 

A pseudo-object mechanism allows playback of a file. The given directory is opened. Two properties are available once the file open: the pointer can be used with other functions such as readdir (), rewinddir () and closedir (). The folder path is the path provided during the construction of the object.

[Warner]

While defining the classes or the constants, you should keep in mind about the Special classes. You cannot use some ID's that belong to the special classes. The following IDs should not be used as class name because of their role :

• Self
• parent
• Closure

The closure class is used for the internal implementation of anonymous functions. The class has a constructor that prohibits manual creation of the object and calls the method on invoke call.

[Modifier]

I would like to discuss about the predefined constants, since I have some knowledge about it. Predefined Constants are defined by the PHP core. The following are some predefined constants that are available on PHP 5.2.7 :

• PHP_VERSION (string)
• PHP_MAJOR_VERSION (integer)
• PHP_MINOR_VERSION (integer)
• PHP_RELEASE_VERSION (integer)
• PHP_VERSION_ID (integer)
• PHP_EXTRA_VERSION (string)
• PHP_ZTS (integer)
• PHP_DEBUG (integer)

[Reegan]

I am providing some more predefined constants that was available since PHP 5.3.0 :

• PHP_WINDOWS_VERSION_MAJOR (integer)
• PHP_WINDOWS_VERSION_MINOR (integer)
• PHP_WINDOWS_VERSION_BUILD (integer)
• PHP_WINDOWS_VERSION_PLATFORM (integer)
• PHP_WINDOWS_VERSION_SP_MAJOR (integer)
• PHP_WINDOWS_VERSION_SP_MINOR (integer)
• PHP_WINDOWS_VERSION_SUITEMASK (integer)