Question

Possible Duplicate:
can't access global variables inside a usort function?

I’ve experienced this problem more then one time now, and I this time I couldnt figure out how to get around it.

$testing = "hej";
function compare($b, $a)
{
    global $testing;
    echo '<script>alert(\'>'.$testing.'<\');</script>';
}

Why does this not show a alertbox with “>hej<“, for me it shows “><“.

Also, this is a function that is call from uasort as second parameter.

Answer 1

The answer is simple: don’t use globals.

If you want access to that variable, and to change the value of that variable, pass it as a parameter by reference:

<?php
$testing = "hej";

function compare($b, $a, &$testing) {
    $testing = "def";
}

compare(1, 2, $testing);

echo $testing; // result: "def"

If you just want the value, pass it by value:

<?php
$testing = "hej";

function compare($b, $a, $testing) {
    $testing = "def";
}

compare(1, 2, $testing);

echo $testing; // result: "hej"

Update:

Another option is to pass an object to usort() in an array:

<?php
class mySort {
    public $testing;

    public function compare($a, $b) {
        echo '<script>alert(\'>'.$this->testing.'<\');</script>';
    }
}

$data = array(1, 2, 3, 4, 5);
$sorter = new mySort();
usort($data, array($sorter, 'compare'));