PHP determines whether a class exists function class_exists

If we want to judge whether a class can be used, we can first use the class_exists function to judge. Let’s look at a few examples.

bool class_exists ( string $class_name [, bool $autoload = true ] )

Whether this function The given class is defined and checked, returning true if class_name is a defined class, otherwise returning false.

php example code is as follows:

if (class_exists('myclass')) {

$myclass = new myclass( );

}

function __autoload($class)

{

include($class . '.php');

if ( !class_exists($class, false)) {

                                                                                                                                                                                                                                                  !

$ myclass = new myclass();

}//Open source code phpfensi.com