Using Reflection to Inspect PHP Classes

Reflection inspects class declarations, methods and properties at runtime.

The examples focus on the operation itself, including the important distinction: get_class_methods returns names but not the rich ReflectionMethod descriptors.

What It Does

Use the examples below to observe the behavior on a small dataset before extending it to application code.

Before You Start

Read the input requirements before applying this pattern to production data.

Example 1: Basic Use

Reflection enumerates declarations; inspecting them does not execute a method.

<?php
class Purchase { public function __construct(public int $id) {} public function total(): float { return 19.5; } }
$type = new ReflectionClass(Purchase::class);
foreach ($type->getMethods(ReflectionMethod::IS_PUBLIC) as $method) {
    echo $method->getName() . PHP_EOL;
}

Output from a successful local PHP 8.4 run:

__construct
total

Example 2: Checking Behavior

Reflection enumerates declarations; inspecting them does not execute a method. The reflected member selection changes without executing class business methods.

<?php
class Purchase { public function __construct(public int $id) {} public function total(): float { return 19.5; } }
$type = new ReflectionClass(Purchase::class);
foreach ($type->getProperties(ReflectionProperty::IS_PUBLIC) as $method) {
    echo $method->getName() . PHP_EOL;
}

Output from a successful local PHP 8.4 run:

id

Example 3: Practical Example

Reflection enumerates declarations; inspecting them does not execute a method. The reflected member selection changes without executing class business methods.

<?php
class Purchase { public function __construct(public int $id) {} public function total(): float { return 19.5; } }
$type = new ReflectionClass(Purchase::class);
foreach ($type->getMethods() as $method) {
    echo $method->getName() . PHP_EOL;
}

Output from a successful local PHP 8.4 run:

__construct
total

Important Behavior and Edge Cases

Reflection reports metadata; invoking reflected methods still executes application code and may have side effects.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Reflection inspects class declarations, methods and properties at runtime.
• Reflection reports metadata; invoking reflected methods still executes application code and may have side effects.
• get_class_methods returns names but not the rich ReflectionMethod descriptors.

Use Using Reflection to Inspect PHP Classes when its documented behavior matches the problem. Test the relevant edge cases in your own runtime before deploying it.