Using the class_exists Function
The class_exists() function is used to determine whether or not a class is defined in the script. It returns a boolean value of either TRUE or FALSE.
demo.php
<?php
include_once("cart.php");
if(class_exists("cart")){
$shopping_cart = new cart();
echo $shopping_cart->store;
} else {
echo '"cart" class does not exist';
}
?>
cart.php
<?php
class cart {
public $store = "Spacely Sprockets";
public $items = array();
}
?>