Question

We wrote some code involving usort which works fine on our development systems (PHP 5.2.8), but are experiencing a problem on our live systems (PHP 5.2.0):

// Sort by distance usort($locations, 'Interpolator::sortByDistance'); 

calls the method (within the same class Interpolator):

private static function sortByDistance($a, $b) {     $return = 0;     if($a['distance'] > $b['distance']) {         $return = 1;     } else if ($a['distance'] < $b['distance']) {         $return = -1;     }     return $return; }         

On our live systems, this returns a completely arbitrarily sorted array, the original order is disturbed, but still not sorted by distance.

I cannot find any reference to a PHP bug fixed between 5.2.0 and 5.2.8 relevant to this problem.

Where might this problem be coming from? Can I fix this short of writing a sorting function myself?

Answer 1

The only think I can think of is that you should be using this:

usort($locations, array('Interpolator', 'sortByDistance'));