PHP Manual: class

Description

function class_alias(string $class, string $alias, bool $autoload = true): bool

Creates an alias named alias based on the user defined class class. The aliased class is exactly the same as the original class.

The class alias cannot be any of the PHP reserved words.

Note:
As of PHP 8.3.0, class_alias() also supports creating an alias of a PHP internal class.

Parameters

class: The original class.
alias: The alias name for the class.
autoload: Whether to autoload if the original class is not found.

Return Values

Returns true on success or false on failure.

Changelog

Version	Description
8.3.0	class_alias() now supports creating an alias of an internal class.

Examples

Example #1 class_alias() example

<?php

class Foo { }

class_alias('Foo', 'Bar');

$a = new Foo;
$b = new Bar;

// the objects are the same
var_dump($a == $b, $a === $b);
var_dump($a instanceof $b);

// the classes are the same
var_dump($a instanceof Foo);
var_dump($a instanceof Bar);

var_dump($b instanceof Foo);
var_dump($b instanceof Bar);

?>

The above example will output:

bool(true)
bool(false)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

Notes

Note:
Class names are case-insensitive in PHP, and this is reflected in this function. Aliases created by class_alias() are declared in lowercase. This means that for a class MyClass, the class_alias('MyClass', 'MyClassAlias') call will declare a new class alias named myclassalias.