How to remove the two duplicate values

Here is the result

$help_brother="30,45,12,13,14,15";
$force_world = '45,12,15';

$help_brother_array = explode(',', $help_brother);
$force_world_array = explode(',', $force_world);


$Result = array_diff($help_brother_array, $force_world_array);
echo implode(",",$Result);

You can get the following result.

If it helps then upvode the answer.