PHP - Ds Deque filter() Function

Ds\Deque::filter() function can create a new deque by using the callable to determine which values to include.

Syntax

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

Ds\Deque::filter() function can return a new deque containing all values in which either a callback returned true, or all values that convert to true if a callback has not provided.

Example 1

<?php 
   $deque = new \Ds\Deque([1, 2, 3, 4, 5]); 
   echo("The elements in the deque: \n"); 
   
   print_r($deque); 
   print_r($deque->filter(function($value) { 
      return $value % 2 == 0; 
   })); 
?>

Example 2

<?php 
   $deque = new \Ds\Deque([10, 20, 8, 40, 5, 70 ]);  
   echo("The elements in the deque: \n"); 
   print_r($deque); 
   print_r($deque->filter(function($value) { 
      return $value % 10 != 0; 
   }));  
?>