Ds\Vector::filter
(PECL ds >= 1.0.0)
Ds\Vector::filter — Creates a new vector using a callable to determine which values to include.
説明
Creates a new vector using a callable to determine which values to include.
パラメータ
-
callback -
Optional callable which returns
TRUEif the value should be included,FALSEotherwise.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)
}
忘却曲線を使ってこの知識を確実に記憶に残す
