PHP | class_exists() Function

0 0 1 minute read

The class_exists() function is an inbuilt function in PHP which is used to check whether the given class is defined or not.

Syntax:

bool class_exists( string $class_name, bool $autoload = TRUE )

Parameters: This function accept two parameters as mentioned above and described below:

$class_name: It holds the class name which need to check their existence.
$autoload: It checks whether the __autoload is called or not by default.

Return Value: This function returns True if class name is defined otherwise returns False.

Below programs illustrate the class_exists() function in PHP:

Program 1:

<?php 
  
// Create a class 
class GFG { 
    public $Geek_name = "Welcome to zambiatek";  
}  
  
// Check class name exist or not 
if(class_exists('GFG')) { 
    echo "Class name exists"; 
} 
else { 
    echo "Class name does not exist"; 
} 
  
?> 

Output:

Class name exists

Program 2:

<?php 
  
// Creating class  
class GFG {  
    public $data1;  
    public $data2;  
    public $data3;  
} 
  
if(class_exists('GFG')) { 
  
    // Creating an object  
    $obj = new GFG(); 
  
    // Set values of $obj object  
    $obj->data1 = "Geeks";  
    $obj->data2 = "for";  
    $obj->data3 = "Geeks";  
  
    // Print values of $obj object  
    echo "$obj->data1  \n$obj->data2  \n$obj->data3";  
} 
else { 
    echo "Class does not exist"; 
} 
  
?> 