Quick Reference
The PHP usort() function sorts an array by values using a user-defined comparison function.
<?php
function my_sort($a, $b) {
if ($a == $b) return 0;
return ($a < $b) ? -1 : 1;
}
$sort = array('Num 4' => 9, 'Num 2' => 4, 'Num 3' => 7, 'Num 1' => 1);
usort($sort, 'my_sort');
print_r($sort);
?>Note
Arrays count starting from zero NOT one. So item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on.
Output
Array ( [0] => 1 [1] => 4 [2] => 7 [3] => 9 )Syntax
usort(array, callback)Parameters
| Parameter | Description |
|---|---|
| array | Specifies an array (required) |
| callback | A comparison function that returns an integer <, =, or > than 0 if the first argument is <, =, or > than the second argument (required) |
PHP Notes:
- When using PHP, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
- Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.