PHP extension_loaded() Function: Usage and Examples

Checks whether a named extension is loaded in the current PHP runtime.

What Is extension_loaded() in PHP?

Checks whether a named extension is loaded in the current PHP runtime.

Its syntax is:

extension_loaded(string $extension): bool

Parameters:

• $extension — Accepted as string; required argument.

Return type: bool. This checks installation but not necessarily configuration or service readiness.

Availability: Core PHP.

Example 1: Basic Usage

<?php

var_dump(extension_loaded("json"));

Output:

bool(true)

This checks installation but not necessarily configuration or service readiness.

Example 2: A Different Input

<?php

var_dump(extension_loaded("nonexistent_extension"));

Output:

bool(false)

This checks installation but not necessarily configuration or service readiness.

Practical Example: Applying It in a Program

<?php

$optionalFeatures = ["intl", "mbstring", "curl"]; foreach ($optionalFeatures as $extensionName) { echo $extensionName . ": " . (extension_loaded($extensionName) ? "ready" : "missing") . PHP_EOL; }

Output:

intl: missing
mbstring: missing
curl: missing

This checks installation but not necessarily configuration or service readiness.

Important Behavior and Edge Cases

• Key behavior: This checks installation but not necessarily configuration or service readiness.
• Environment: Core PHP.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• Checks whether a named extension is loaded in the current PHP runtime.
• This checks installation but not necessarily configuration or service readiness.
• Core PHP.

Summary: This checks installation but not necessarily configuration or service readiness.