Java披萨程序开发问题：移除已选配料后不再显示菜单选项

核心问题解决思路 #

要实现「选完的配料不再显示在菜单里」，可以新增一个布尔数组标记每个配料的选中状态。每次打印菜单时仅输出未被标记为已选的配料；用户选择配料后，将对应位置的标记设为true，后续循环就不会再显示该配料。

修改后的完整代码 #

import java.util.Scanner;

public class PizzaCustomizer {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.println("\"---------------------\"");
        System.out.println("\"Create Your Own Pizza\"");
        System.out.println("\"---------------------\"");
        
        char userChar = 'y';
        String[] toppings = {"\"diced onion\"", "\"green pepper\"", "\"pepperoni\"", "\"sliced mushrooms\"", "\"jalapenos\"", "\"pineapple\"", "\"dry red pepper\"", "\"basil\""};
        String[] choices = { "\"A. \"", "\"B. \"", "\"C. \"", "\"D. \"", "\"E. \"", "\"F. \"", "\"G. \"", "\"H. \""};
        // 新增数组标记配料是否已被选择
        boolean[] isToppingSelected = new boolean[toppings.length];

        while (userChar == 'y') {
            System.out.println("\"\nChoose your favorite toppings\"");

            // 仅打印未被选中的配料
            for (int i=0; i<choices.length; ++i) { 
                if (!isToppingSelected[i]) {
                    System.out.println(choices[i] + toppings[i]);   
                }
            }

            System.out.println("\"\nEnter a choice: \"");
            String userToppings = sc.nextLine();
            // 去掉输入中的引号和空白，避免判断出错
            userToppings = userToppings.replace("\"", "").trim();

            if (userToppings.equalsIgnoreCase("A")) {
                System.out.println("\"Please choose one amount: \"");
                System.out.println("\"a. 1/8 cup                 b. 1/4 cup\"");
                String amountChoice = sc.nextLine().replace("\"", "").trim();
                choices[0] = amountChoice.equalsIgnoreCase("A") ? "\"1/8 cup\"" : "\"1/4 cup\"";
                // 标记该配料已选
                isToppingSelected[0] = true;
                System.out.println("\"Would you like to add more toppings? Type Y for yes or any other key to submit your recipe.\"");
                // 处理next()后的换行残留问题
                userChar = sc.next().charAt(0);
                sc.nextLine();
            } else if (userToppings.equalsIgnoreCase("B")) {
                System.out.println("\"Please choose one amount: \"");
                System.out.println("\"a. 1/8 cup                 b. 1/4 cup\"");
                String amountChoice = sc.nextLine().replace("\"", "").trim();
                choices[1] = amountChoice.equalsIgnoreCase("A") ? "\"1/8 cup\"" : "\"1/4 cup\"";
                isToppingSelected[1] = true;
                System.out.println("\"Would you like to add more toppings? Type Y for yes or any other key to submit your recipe.\"");
                userChar = sc.next().charAt(0);
                sc.nextLine();
            } else if (userToppings.equalsIgnoreCase("C")) {
                // 按A、B的格式继续补充C到H的逻辑
                System.out.println("\"Please choose one amount: \"");
                System.out.println("\"a. 1/8 cup                 b. 1/4 cup\"");
                String amountChoice = sc.nextLine().replace("\"", "").trim();
                choices[2] = amountChoice.equalsIgnoreCase("A") ? "\"1/8 cup\"" : "\"1/4 cup\"";
                isToppingSelected[2] = true;
                System.out.println("\"Would you like to add more toppings? Type Y for yes or any other key to submit your recipe.\"");
                userChar = sc.next().charAt(0);
                sc.nextLine();
            } 
            // 此处继续补充D到H的判断逻辑...
            else {
                System.out.println("\"You did not enter a valid topping choice\"");
            }
        }

        // 补全未定义的食谱变量（示例值）
        String crustType = "\"Thin Crust\"";
        String sauceType = "\"Tomato Sauce\"";
        String sauceAmount = "1/2 cup";
        String cheese = "\"Mozzarella Cheese\"";
        String cheeseAmount = "1 cup";

        System.out.println("\"Your pizza recipe is: \"");
        System.out.println(crustType + "\"\t1 \"");
        System.out.println(sauceType + "\"\t\"" + sauceAmount);
        System.out.println(cheese + "\"\t\t\"" + cheeseAmount);
          
        // 仅打印用户实际选择的配料
        for (int i=0; i<toppings.length; i++) {
            if (isToppingSelected[i]) {
                System.out.println(toppings[i] + "\"\t\t\"" + choices[i]);   
            }
        }
    }
}

关键修改点说明 #

1. 选中状态标记：新增boolean[] isToppingSelected数组，初始值全为false，用户选完配料后将对应位置设为true。
2. 菜单过滤打印：循环打印菜单时增加if (!isToppingSelected[i])判断，只显示未被选择的配料。
3. 输入稳定性优化：去掉输入字符串中的引号和空白，避免用户输入带/不带引号导致判断失败；处理sc.next()后的换行残留，防止后续输入读取异常。
4. 食谱输出优化：打印最终食谱时仅输出用户选择的配料，避免无效信息干扰。

额外可读性与功能性建议 #

• 规范命名：将类名test改为PizzaCustomizer，变量名使用语义化命名（如userToppings改为selectedOption），符合Java编码规范。
• 补全配料逻辑：当前代码仅处理了A、B、C选项，需按相同格式补全D到H的判断逻辑。
• 简化重复代码：虽然还没学自定义方法，但可以把配料选择、用量设置的重复代码暂时复制复用，后续学习方法后再统一重构。

内容的提问来源于stack exchange，提问作者L3i5ur3L3