Ds\Sequence::map

(PECL ds >= 1.0.0)

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

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

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

callback

mixed callback ( mixed $value )

A callable to apply to each value in the sequence.

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

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

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

Example #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);
?>

以上例程的输出类似于：

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