Sort an array so that null values always come last

Question

I need to sort an array of strings, but I need it so that null is always last. For example, the array:

var arr = [a, b, null, d, null]

When

Answer 1

Do it like:

        var arr = [a, b, null, d, null]

        foreach ($arr as $key => $value) {
           if($value == null)
           unset($arr[$key]);
           $arr[] = $value;

        }
        // rebuild array index
        $arr = array_values($arr);

        echo '
';print_r($arr);die;