どうしてあなたの共通化は間違っているのか：第1章「単一責任原則の有用性」 - Qiita

class DiscountManager { static int getDiscountPrice(int price, boolean isSummer) { if (isSummer) { int discountPrice = price - 300; if (discountPrice < 0) { discountPrice = 0; } return discountPrice; } return (int)(price * (1.00 - 0.04)); } } class DiscountManager { static int getDiscountPrice(int price, boolean isSummer) { if (isSummer) { return getSummerDiscount(price) } return getRegularDiscoun