PHP | uksort() Function

PHP uksort() Function

Hello folks! welcome back to a new edition of our tutorial on PHP. In this tutorial guide, we are going to be studying about the PHP uksort() Function.

The built-in PHP uksort() function sorts an array by element keys making use of user-defined comparison function.


Following below is the syntax to use this function -

uksort ( $array, $cmp_function )

Parameter Details

Sr.NoParameter & Description


It specifies an array.



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

This function returns TRUE on success, or FALSE on failure.


Try out the below example -

   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");


When the above code is executed, it will produce the following result -

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

Alright guys! This is where we are going to be rounding up for this tutorial post. In our next tutorial, we are going to be discussing about the PHP usort() Function.

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