Php/docs/ds-sequence.filter
Ds\Sequence::filter
(PECL ds >= 1.0.0)
Ds\Sequence::filter — Creates a new sequence using a callable to determine which values to include
Description
abstract public Ds\Sequence::filter
([ callable $callback
] ) : Ds\Sequence
Creates a new sequence using a callable to determine which values to include.
Parameters
callback
callback ( mixed
$value
) : boolOptional callable which returns
TRUE
if the value should be included,FALSE
otherwise.If a callback is not provided, only values which are
TRUE
(see converting to boolean) will be included.
Return Values
A new sequence containing all the values for which
either the callback
returned TRUE
, or all values that
convert to TRUE
if a callback
was not provided.
Examples
Example #1 Ds\Sequence::filter() example using callback function
<?php$sequence = new \Ds\Vector([1, 2, 3, 4, 5]);var_dump($sequence->filter(function($value) { return $value % 2 == 0;}));?>
The above example will output something similar to:
object(Ds\Vector)#3 (2) { [0]=> int(2) [1]=> int(4) }
Example #2 Ds\Sequence::filter() example without a callback function
<?php$sequence = new \Ds\Vector([0, 1, 'a', true, false]);var_dump($sequence->filter());?>
The above example will output something similar to:
object(Ds\Vector)#2 (3) { [0]=> int(1) [1]=> string(1) "a" [2]=> bool(true) }