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PHP usort() Function Usage and Example

The usort() function sorts the values in the array using a user-defined comparison function

Syntax

usort ($array, $cmp_function)

Definition and Usage

The usort() function sorts an array using a user-defined comparison function. This function assigns new keys to the elements of the array. Existing keys will be deleted.

Parameter

Serial Number	Parameters and Description
1	array(Required) It specifies an array.
2	cmp_function(Required) Useful defined function, used to compare values and sort them. Return 0 if a = b Return if a > b1 Return if a < b-1

Return Value

Return TRUE on success, FALSE on failure.

Online Example

Example

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

Test and See‹/›

Output Result:

Array ( [0] => orange [1] => lemon [2] => banana )

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