The Ds\Sequence::filter() function is an inbuilt function in PHP which is used to create new sequence using filter function.
Syntax:
Ds\Sequence abstract public Ds\Sequence::filter ([ callable $callback ] )
Parameter: It is an optional parameter and it returns True if the value should be included, False otherwise.
Return value: This function returns 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.
Below programs illustrate the Ds\Sequence::filter() function in PHP:
Example 1:
<?php // Create new sequence $seq = new \Ds\Vector([10, 20, 30, 40, 50]); // Display new sequence using filter function var_dump( $seq ->filter( function ( $val ) { return $val % 4 == 0; })); ?> |
Output:
object(Ds\Vector)#3 (2) { [0] => int(20) [1] => int(40) }
Example 2:
<?php // Create new sequence $seq = new \Ds\Vector([2, 5, 4, 8, 3, 9]); // Display new sequence using filter function var_dump( $seq ->filter( function ( $val ) { return $val ; })); ?> |
Output:
object(Ds\Vector)#3 (6) { [0] => int(2) [1] => int(5) [2] => int(4) [3] => int(8) [4] => int(3) [5] => int(9) }
Reference: http://php.net/manual/en/ds-sequence.filter.php