array_reduce() function in php

array_reduce() function of PHP is used to reduce a PHP array into a single variable with the help of a user define function or a callback function. It is an inbuilt function of PHP.

Syntax:

here,

• $array is a PHP array. It is mandatory
• user_function is the user define function which has conditions to be applied on an array. It is also mandatory.
• $initial is the value which send to the user define function. It is optional.

Example 1:

<?php
// This example add all elements of array and return their addition
function user_function($x,$y)
{
  $x = $x + $y;
  return $x;
}
$arr = array(1,2,3,4,5,6,7,8,9,10);
$result=array_reduce($arr,"user_function","0");
echo 'Sum of all values of $arr is '.$result;
?>

Output:

Example 2:

<?php
// reduce all values of array into a single string separated by commas
function user_function($x,$y)
{
  $x = $x.','.$y;
  return $x;
}
$arr = array(1,2,3,4,5,6,7,8,9,10);
$result=array_reduce($arr,"user_function","0");
echo $result;
?>

Output: