public class TipCalculator { public static Integer calculateTip(double amount, String rating) { int tip; String newRating = rating.toLowerCase(); switch (newRating) { case "terrible": tip = 0; break; case "poor": tip = 5; break; case "good": tip = 10; break; case "great": tip = 15; break; case "excellent": tip = 20; break; default: return null; } int finalTip = (int) (amount * tip / 100); return finalTip; } }