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<Ds\Deque::allocateDs\Deque::capacity>
^Ds\DequeLast updated: Mon, 26 Oct 2026

Ds\Deque::apply

(PECL ds >= 1.0.0)

Ds\Deque::apply — Updates all values by applying a callback function to each value

Description

public function Ds\Deque::apply(callable $callback): void

Updates all values by applying a callback function to each value in the deque.

Parameters

callback

function callback(mixed $value): mixed

A callable to apply to each value in the deque.

The callback should return what the value should be replaced by.

Return Values

No value is returned.

Examples

Example #1 Ds\Deque::apply() example

<?php
$deque = new \Ds\Deque([1, 2, 3]);
$deque->apply(function($value) { return $value * 2; });

print_r($deque);
?>

The above example will output something similar to:

Ds\Deque Object
(
    [0] => 2
    [1] => 4
    [2] => 6
)

<Ds\Deque::allocateDs\Deque::capacity>
^Ds\DequeLast updated: Mon, 26 Oct 2026