PHP - Ds Set reduce() Function

Ds\Set::reduce() function can reduce a set to single value by using callback function.

Syntax

public mixed Ds\Set::reduce( callable $callback [, mixed $initial ] )

Ds\Set::reduce() function can return the value of final callback.

Example 1

<?php  
   $set = new \Ds\Set([10, 20, 30, 40]);  
   echo("The original set elements: \n");  
   print_r($set);  
   
   $func = function($carry, $element) {  
      return $carry * $element;  
   };  
   
   echo("\n The set after reducing to single element: \n");  
   var_dump($set->reduce($func, 10));
?> 

Example 2

<?php  
   $set = new \Ds\Set([10, 20, 30, 40, 50]);  
   
   echo("The set elements are: \n");  
   print_r($set);  
   
   echo("\n An element after performing operation: \n");  
   
   var_dump($set->reduce(function($carry, $element) {  
      return $carry + $element + 2;  
   }));  
?>