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