extension_loaded
Checks whether a PHP extension is loaded.
Syntax
extension_loaded(string $extension): boolParameters
| Parameter | Type | Description |
|---|---|---|
| $extension | string | The extension name: `mbstring`, `curl`, `pdo_mysql`, `gd`. |
Return value
bool`true` if the extension is available.
Examples
Checking before use:
<?php
var_dump(extension_loaded('json'));
var_dump(extension_loaded('no_such_extension'));Output:
bool(true)
bool(false)Notes
The php -m command lists every extension. A project's requirements go into composer.json: "ext-mbstring": "*".
See also
- function_exists — Checks whether a function is defined.
- class_exists — Checks whether a class is defined.
- version_compare — Compares two version numbers.
Related recipes
In the tutorial
- Namespaces and Composer — How a PHP project is organised — namespaces, PSR-4 class autoloading and installing libraries with Composer.