Ds\Sequence::map

(PECL ds >= 1.0.0)

Ds\Sequence::map — Returns the result of applying a callback to each value

説明

abstract public function Ds\Sequence::map(callable $callback): Ds\Sequence

Returns the result of applying a callback function to each value in the sequence.

パラメータ

callback

function callback(mixed $value): mixed

A callable to apply to each value in the sequence. The callable should return what the new value will be in the new sequence.

戻り値

The result of applying a callback to each value in the sequence.

注意: The values of the current instance won't be affected.

例

例1 Ds\Sequence::map() example

<?php
$sequence = new \Ds\Vector([1, 2, 3]);

print_r($sequence->map(function($value) { return $value * 2; }));
print_r($sequence);
?>

上の例の出力は、 たとえば以下のようになります。

Ds\Vector Object
(
    [0] => 2
    [1] => 4
    [2] => 6
)
Ds\Vector Object
(
    [0] => 1
    [1] => 2
    [2] => 3
)