class_exists

(PHP 4, PHP 5, PHP 7, PHP 8)

class_existsChecks if the class has been defined

Description

class_exists(string $class, bool $autoload = true): bool

This function checks whether or not the given class has been defined.

Parameters

class

The class name. The name is matched in a case-insensitive manner.

autoload

Whether to call __autoload by default.

Return Values

Returns true if class is a defined class, false otherwise.

Examples

Example #1 class_exists() example

<?php
// Check that the class exists before trying to use it
if (class_exists('MyClass')) {
    
$myclass = new MyClass();
}

?>

Example #2 autoload parameter example

<?php
spl_autoload_register
(function ($class_name) {
    include 
$class_name '.php';

    
// Check to see whether the include declared the class
    
if (!class_exists($class_namefalse)) {
        throw new 
LogicException("Unable to load class: $class_name");
    }
});

if (
class_exists(MyClass::class)) {
    
$myclass = new MyClass();
}

?>

See Also

Here you can write a comment


Please enter at least 10 characters.
Loading... Please wait.
* Pflichtangabe
There are no comments available yet.

Was genau bedeutet "Vibe Coding"? Ein tiefgehender Blick für Entwickler

In der Welt der Softwareentwicklung gibt es unzählige Wege, wie man an ein Projekt herangeht. Manche schwören auf strikte Planung, andere auf bewährte Algorithmen und wieder andere lassen sich von etwas ganz anderem leiten: ihrem Gefühl. ...

admin

Autor : admin
Category: Software & Web-Development

PHP cURL Tutorial: Using cURL to Make HTTP Requests

cURL is a powerful PHP extension that allows you to communicate with different servers using various protocols, including HTTP, HTTPS, FTP, and more. ...

TheMax

Autor : TheMax
Category: PHP-Tutorials

Midjourney Tutorial - Instructions for beginners

There is an informative video about Midjourney, the tool for creating digital images using artificial intelligence, entitled "Midjourney tutorial in German - instructions for beginners" ...

Mike94

Autor : Mike94
Category: KI Tutorials

Publish a tutorial

Share your knowledge with other developers worldwide

Share your knowledge with other developers worldwide

You are a professional in your field and want to share your knowledge, then sign up now and share it with our PHP community

learn more

Publish a tutorial