The ReflectionFunction class

(PHP 5, PHP 7, PHP 8)

Introduction

The ReflectionFunction class reports information about a function.

Class synopsis

class ReflectionFunction extends ReflectionFunctionAbstract {
/* Constants */
public const int IS_DEPRECATED;
/* Inherited properties */
public string $name;
/* Methods */
public __construct(Closure|string $function)
public static export(string $name, string $return = ?): string
public invoke(mixed ...$args): mixed
public invokeArgs(array $args): mixed
public isAnonymous(): bool
public isDisabled(): bool
public __toString(): string
/* Inherited methods */
}

Predefined Constants

ReflectionFunction Modifiers

ReflectionFunction::IS_DEPRECATED

Indicates deprecated functions.

Changelog

Version Description
8.0.0 ReflectionFunction::export() was removed.

Table of Contents

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User Contributed Notes 2 notes

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7
a dot lucassilvadeoliveira at gmail dot com
3 years ago
We can use this functionality to automatically pass arguments to our function based on some data structure.

NOTE: I am using a php 8.0> feature called "Nameds parameter"

<?php

$valuesToProcess
= [
'name' => 'Anderson Lucas Silva de Oliveira',
'age' => 21,
'hobbie' => 'Play games'
];

function
processUserData($name, $age, $job = "", $hobbie = "")
{
$msg = "Hello $name. You have $age years old";
if (!empty(
$job)) {
$msg .= ". Your job is $job";
}

if (!empty(
$hobbie)) {
$msg .= ". Your hobbie is $hobbie";
}

echo
$msg . ".";
}

$refFunction = new ReflectionFunction('processUserData');
$parameters = $refFunction->getParameters();

$validParameters = [];
foreach (
$parameters as $parameter) {
if (!
array_key_exists($parameter->getName(), $valuesToProcess) && !$parameter->isOptional()) {
throw new
DomainException('Cannot resolve the parameter' . $parameter->getName());
}

if(!
array_key_exists($parameter->getName(), $valuesToProcess)) {
continue;
}

$validParameters[$parameter->getName()] = $valuesToProcess[$parameter->getName()];
}

$refFunction->invoke(...$validParameters);
?>

Results in:

Hello Anderson Lucas Silva de Oliveira. You have 21 years old. Your hobbie is Play games.
up
-2
Lorenz R.S.
13 years ago
Here is a concise example of ReflectionFunction usage for Parameter Reflection / introspection (e.g. to automatically generate API descriptions)

<?php
$properties
= $reflector->getProperties();
$refFunc = new ReflectionFunction('preg_replace');
foreach(
$refFunc->getParameters() as $param ){
//invokes ■ReflectionParameter::__toString
print $param;
}
?>

prints:

Parameter #0 [ <required> $regex ]
Parameter #1 [ <required> $replace ]
Parameter #2 [ <required> $subject ]
Parameter #3 [ <optional> $limit ]
Parameter #4 [ <optional> &$count ]
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