php class to determine whether there is a function class_exists

Source: Internet
Author: User
Keywords Network programming PHP tutorial
Tags check checks class class_exists function network network programming php

php tutorial to determine whether the existence of class function class_exists
// bool class_exists (string $ class_name [, bool $ autoload = true])
// Whether this function is given class is defined to check. this function checks whether or not the given class has been defined.

// returns true if class_name is a defined class, false otherwise.
// instance

if (class_exists ('myclass')) {
$ myclass = new myclass ();
}

function __autoload ($ class)
{
include ($ class. '.php');

// check to see whether the include declared the class
if (! class_exists ($ class, false)) {
trigger_error ("unable to load class: $ class", e_user_warning);
}
}

if (class_exists ('myclass')) {
$ myclass = new myclass ();
}

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