10/22/300
10/21/300
9/5/5/6
9/5/5/6
10/21/300
10/22/300
$element = explode('/', $item);
[9,5,5,6]
$array = [
'10/22/300',
'10/21/300',
'9/5/5/6'
];
usort($array, function($a, $b) {
$a = array_sum(explode('/', $a));
$b = array_sum(explode('/', $b));
return ($a == $b ? 0 : ($a < $b ? -1 : 1));
});
print_r($array);