Ds\Deque::filter
(PECL ds >= 1.0.0)
Ds\Deque::filter — Creates a new deque using a callable to determine which values to include
說明
Creates a new deque using a callable to determine which values to include.
參數
-
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.
返回值
A new deque containing all the values for which
either the callback
returned true
, or all values that
convert to true
if a callback
was not provided.
範例
示例 #1 Ds\Deque::filter() example using callback function
<?php
$deque = new \Ds\Deque([1, 2, 3, 4, 5]);
var_dump($deque->filter(function($value) {
return $value % 2 == 0;
}));
?>
以上例程的輸出類似於:
object(Ds\Deque)#3 (2) { [0]=> int(2) [1]=> int(4) }
示例 #2 Ds\Deque::filter() example without a callback function
<?php
$deque = new \Ds\Deque([0, 1, 'a', true, false]);
var_dump($deque->filter());
?>
以上例程的輸出類似於:
object(Ds\Deque)#2 (3) { [0]=> int(1) [1]=> string(1) "a" [2]=> bool(true) }