Ds\Vector::map

(PECL ds >= 1.0.0)

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

public Ds\Vector::map(callable $callback): Ds\Vector

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

callback

callback(mixed $value): mixed

A callable to apply to each value in the vector.

The callable should return what the new value will be in the new vector.

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

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

示例 #1 Ds\Vector::map() example

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

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

以上示例的输出类似于：

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