ReflectionParameter::allowsNull

(PHP 5, PHP 7, PHP 8)

ReflectionParameter::allowsNull — Vérifie si la valeur null est autorisée comme valeur du paramètre

Description

public ReflectionParameter::allowsNull(): bool

Vérifie si la valeur null est autorisée comme valeur du paramètre.

Liste de paramètres

Cette fonction ne contient aucun paramètre.

Valeurs de retour

true si la valeur null est autorisée comme valeur du paramètre, false sinon.

Voir aussi

ReflectionParameter::isOptional() - Vérifie si le paramètre est optionnel

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User Contributed Notes 2 notes

down

Geoffrey LAURENT ¶

12 years ago

The allowsNull method look if arguments have a type. 
If a type is defined, null is allowed only if default value is null.

 <?php 
function myfunction ( $param ) {
    
}

echo (new ReflectionFunction("myfunction"))->getParameters()[0]->allowsNull() ? "true":"false";

?>

Result : true

<?php 
function myfunction ( stdClass $param ) {
    
}

echo (new ReflectionFunction("myfunction"))->getParameters()[0]->allowsNull() ? "true":"false";

?>

Result : false

<?php
function myfunction ( stdClass $param = null ) {
    
}

echo (new ReflectionFunction("myfunction"))->getParameters()[0]->allowsNull() ? "true":"false";
?>

Result : true

down

those-cradle-frays at duck dot com ¶

1 day ago

The note about detecting nullability on a parameter predates "?type" and other union types. Null isn't expected to be the default if there's a defined type that allows it ("?int", "mixed", "int|string|null", etc.).

<?php
function foo($bar) { }
(new ReflectionFunction('foo'))->getParameters()[0]->allowsNull();
// true

function foo(string $bar) { }
(new ReflectionFunction('foo'))->getParameters()[0]->allowsNull();
// false

function foo(?string $bar) { }
(new ReflectionFunction('foo'))->getParameters()[0]->allowsNull();
// true

function foo(?string $bar = 'baz') { }
(new ReflectionFunction('foo'))->getParameters()[0]->allowsNull();
// true (default string doesn't matter)

// Note: Raises E_DEPRECATED, implicitly making parameter nullable
function foo(string $bar = null) { }
(new ReflectionFunction('foo'))->getParameters()[0]->allowsNull();
// true (even in strict mode, PHP <= 8)
?>

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