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 Ds\Sequence::filter ([ callable $callback ] )
Creates a new sequence using a callable to determine which values to include.
Parameters
-
callback
-
bool callback ( mixed $value )
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.
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) }
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https://secure.php.net/manual/en/ds-sequence.filter.php