Price Calculator based on Quantity [closed]

Answer 1

Instead of defining every condition in an IF statement, I would suggest defining constants for every stage:

    
    


 constant("STAGE_".$i."_MIN") && $_POST['qnt'] <= constant("STAGE_".$i."_MAX")) {
        echo $_POST['qnt'] * constant("STAGE_".$i."_MULTIPLIER");
    }
    elseif ($_POST['qnt'] < constant("STAGE_".MIN_STAGE."_MIN") || $_POST['qnt'] > constant("STAGE_".MAX_STAGE."_MAX")) {
        die ('Must be between ' . constant("STAGE_".MIN_STAGE."_MIN") . ' AND ' . constant("STAGE_".MAX_STAGE."_MAX"));
    }
}