Ds\Set::map

Returns the result of applying a callback to each value

説明

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

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

パラメータ

callback

The callback to apply to each value in the set must have the following signature:

mixed callback(mixed $value)

戻り値

Returns a new Ds\Set instance where each value is the result of applying the callback to each value of the set.

例

例1 Ds\Set::map example

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

var_dump($set->map(function($value) { return $value * 2; }));
var_dump($set);
?>

上の例の出力は、たとえば以下のようになります。

object(Ds\Set)#3 (3) {
  [0]=>
  int(2)
  [1]=>
  int(4)
  [2]=>
  int(6)
}
object(Ds\Set)#1 (3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
}