Introspection in PHP

 Introspection in PHP:

Introspection in PHP offers the useful ability to examine an object's characteristics, such as its name, parent class (if any) properties, classes, interfaces, and methods.
PHP offers a large number of functions that you can use to accomplish the task.
The following are the functions to extract basic information about classes such as their name, the name of their parent class and so on.
In-built functions in PHP Introspection :

Function
Description
class_exists()
Checks whether a class has been defined.
et_class()
Returns the class name of an object.
get parent_class()
Returns the class name of a Return object's parent class.
is_subclass_of()
Checks whether an object has a given parent class.
get_declared_classes() 
Returns a list of all declared classes.

get_class_methods() 
Returns the names of the class methods.
get_class_vars()
Returns the default properties of a class
interface_exists()
Checks whether the interface is defined.
method_exists()
Checks whether an object defines a method.

Example 1:

<?php

if(class_exists('cwipedia'))
{
 $ob=new cwipedia();
 echo "This is cwipedia.in";
}
else
{
 echo "Not exist";
}

?>

Output: Not exist

Example 2:

<?php
class cwipedia
{
 //decl
}
if(class_exists('cwipedia'))
{
 $ob=new cwipedia();
 echo "This is cwipedia.in";
}
else
{
 echo "Not exist";
}

?>

Output: This is cwipedia.in