Ds\Deque::filter

(PECL ds >= 1.0.0)

Ds\Deque::filter Creates a new deque using a callable to determine which values to include

説明

public Ds\Deque::filter ([ callable $callback ] ) : Ds\Deque

Creates a new deque using a callable to determine which values to include.

パラメータ

callback

callback ( mixed $value ) : bool

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.

返り値

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.

例1 Ds\Deque::filter() example using callback function

<?php
$deque 
= new \Ds\Deque([12345]);

var_dump($deque->filter(function($value) {
    return 
$value == 0;
}));
?>

上の例の出力は、 たとえば以下のようになります。

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

例2 Ds\Deque::filter() example without a callback function

<?php
$deque 
= new \Ds\Deque([01'a'truefalse]);

var_dump($deque->filter());
?>

上の例の出力は、 たとえば以下のようになります。

object(Ds\Deque)#2 (3) {
  [0]=>
  int(1)
  [1]=>
  string(1) "a"
  [2]=>
  bool(true)
}