usort function in a class
php
Solution
order_new is a class method not a global function. As the PHP-Manual suggest you can use in this case
usort($data, array($this, "order_new"));
or declare order_new static and use
usort($data, array("myClass", "order_new"));
Problem
I have a function which sorts data in a multidimensional array, as shown below: ``` <?php $data = array(); $data[] = array("name" => "James"); $data[] = array("name" => "andrew"); $data[] = array("name" => "Fred"); function cmp($a, $b) { return strcasecmp($a["name"], $b["name"]); } usort($data, "cmp"); var_dump($data); ?> ``` When i run this, it works as expected, returning the data ordered by name, ascending. However, I need to use this in a class. ``` <?php class myClass { function getData() { // gets all data $this -> changeOrder($data); } function changeOrder(&$data) { usort($data, "order_new"); } function order_new($a, $b) { return strcasecmp($a["name"], $b["name"]); } } ?> ``` When I use this, i get the following warning: Warning: usort() expects parameter 2 to be a valid callback, function 'order_new' not found or invalid function name. When i put the order_new function in the changeOrder function it works fine, but I have problems with Fatal error: Cannot redeclare order_new(), so i cannot use that. Any suggestions?