PHP - Function uksort()

Syntax

uksort ( $array, $cmp_function )

Definition and Usage

The uksort() function sorts an array by the element keys using user defined comparison function.

Parameters

Sr.No	Parameter & Description
1	array(Required) It specifies an array.
2	cmp_function(Required) Use if defined function to compare values and to sort them. The function must return -1, 0, or 1 for this method to work correctly. It should be written to accept two parameters to compare, and it should work something like this − If a = b, return 0 If a > b, return 1 If a < b, return -1

Sr.No

Parameter & Description

array(Required)

It specifies an array.

cmp_function(Required)

Use if defined function to compare values and to sort them.

The function must return -1, 0, or 1 for this method to work correctly. It should be written to accept two parameters to compare, and it should work something like this −

If a = b, return 0
If a > b, return 1
If a < b, return -1

Return Value

It returns TRUE on success or FALSE on failure.

Example

Try out following example −

Live Demo

<?php
   function cmp_function($a, $b) {
      if ($a == $b) return 0;
      return ($a > $b) ? -1 : 1;
   }
   
   $input = array("d"=>"lemon", "a"=>"orange", "b"=>"banana" );
   uksort($input, "cmp_function");
   
   print_r($input);
?>

This will produce the following result −

Array ( [d] => lemon [b] => banana [a] => orange )

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