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(PECL ds >= 1.0.0)
Ds\Set::filter — Creates a new set using a callable to determine which values to include
Creates a new set using a callable to determine which values to include.
callback
Optional callable which returns true
if the value should be included, false
otherwise.
If a callback is not provided, only values which are true
(see converting to boolean)
will be included.
A new set containing all the values for which
either the callback
returned true
, or all values that
convert to true
if a callback
was not provided.
例1 Ds\Set::filter() example using callback function
<?php
$set = new \Ds\Set([1, 2, 3, 4, 5]);
var_dump($set->filter(function($value) {
return $value % 2 == 0;
}));
?>
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 (2) { [0]=> int(2) [1]=> int(4) }
例2 Ds\Set::filter() example without a callback function
<?php
$set = new \Ds\Set([0, 1, 'a', true, false]);
var_dump($set->filter());
?>
上の例の出力は、 たとえば以下のようになります。
object(Ds\Set)#2 (3) { [0]=> int(1) [1]=> string(1) "a" [2]=> bool(true) }