Sort Multi-dimensional array by decimal values

$arr = array(
    array('company' => 'A', 'weight' => 4.6),
    array('company' => 'B', 'weight' => 1.7),
    array('company' => 'C', 'weight' => 3.7),
);

usort($arr, 'order_by_weight');

function order_by_weight($a, $b) {
    return $b['weight'] > $a['weight'] ? 1 : -1;
}

var_dump($arr);

PS: it's not a rocket science - this exact "trick" is used as the first example at http://php.net/usort

You can do this with anonymous function in just one line

$arr = array(
    array('company' => 'A', 'weight' => 4.6),
    array('company' => 'B', 'weight' => 1.7),
    array('company' => 'C', 'weight' => 3.7),
);
usort($arr, function($a, $b) { return $b['weight'] > $a['weight'] ;});

print_r($arr);

Hope this helps :)