Java 简单测验获胜'；Don’不要等待答复

作为在线练习的一部分，我一直在尝试做一个简单的测验。我有两个问题，其中一个if语句应该只接受三种可能结果中的一种，正确答案、错误答案或错误选择

我的问题是，当用户做出错误的选择（如A B或C）并按下Q时，程序会跳过下一个问题，而不等待正确或错误的答案。据我所知，除非满足条件，否则if语句不应允许程序运行，但无论如何，错误的选择仍会转移到下一个问题

请在你的回答中残忍一些，我感觉我学到的方法有点过时了

import java.util.Scanner;

class quiz {
    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String a;
        String b;
        String c;
        String name;
        int score = 0;

        System.out.println("Welcome to your new quiz !");
        System.out.println("What is your name?");
        name = scan.nextLine();
        System.out.println("Welcome " + name + " let's start the quiz !");
        System.out.println("What is Ireland's capitol city?");
        System.out.println("Is it\n\t\tA)Dublin\n\t\tB)Galway\n\t\tC)Cork\n");
        System.out.println("Please select A B or C");
        System.out.println("Your current score is " + score);
        String q;
        q = scan.nextLine();

        if (q.toLowerCase().equals("a")) {
            System.out.println("Correct!");
            score = score + 1;
            System.out.println("Your new score is " + score);
        } else if (q.toLowerCase().equals("b")) {
            System.out.println("Sorry that was incorrect!");
        } else if (q.toLowerCase().equals("c")) {
            System.out.println("Sorry that was incorrect!");
        } else {
            System.out.println("You pressed " + q + " Please choose A B or C");
        }

        System.out.println("Second Question !!");
        System.out.println("What was the currency unit for Ireland before the Euro was introduced?");
        System.out.println("Is it\n\t\tA)Pound\n\t\tB)Dollar\n\t\tC)Punt\n");
        System.out.println("Please select A B or C");
        System.out.println("Your current score is " + score);
        String w;
        w = scan.nextLine();

        if (w.toLowerCase().equals("c")) {
            System.out.println("Correct!");
            score = score + 1;
            System.out.println("Your new score is " + score);
        } else if (w.toLowerCase().equals("b")) {
            System.out.println("Sorry that was incorrect!");
        } else if (w.toLowerCase().equals("a")) {
            System.out.println("Sorry that was incorrect!");
        } else {
            System.out.println("You pressed " + w + " Please choose A B or C");
        }
    }
}

---

您需要在程序中实现一个循环，这样它将不断地询问答案，直到输入有效的响应为止。while循环可以实现这一点，如下所示：

定义一个布尔（真/假）变量，用于跟踪是否做出了有效响应：

boolean validResponse = false;

然后在while循环中使用此选项，在必要时反复提问：

while (!validResponse) {
    q = scan.nextLine();
    if (q.toLowerCase().equals("a")) {
        System.out.println("Correct!");
        score++;
        System.out.println("Your new score is " + score);
        validResponse = true;
    }
    // else if 'b', if 'c', etc.
    if (!validResponse) {
        System.out.println("You pressed " +q+" Please choose A B or C");
    }
}

while循环中的代码将重复运行，直到测试失败-在这种情况下，当

validResponse

设置为true时。此时，程序将继续执行循环后面的任何操作

---

有更好的方法来实现这个程序，但我尽量少修改代码。例如，您可能希望将问题和答案存储在数据结构中，并对其进行迭代，而不是对每个问题重复几乎相同的代码块。

正如我在评论中所说，这里需要一个带有布尔标志的循环。

将

While

条件放置在

Do

循环的底部将确保循环中的代码至少运行一次。 如果将条件放置在顶部，如下所示：

while (guessed){
    // your code goes here
}

    boolean correctAnswer = false;
    do {
        w = scan.nextLine();
        if (w.toLowerCase().equals("c")){
            score++; //same as score = score + 1;
            correctAnswer = true;
            System.out.println("Correct! Your new score is " +score);
        }else if (w.toLowerCase().equals("b")){
            System.out.println("Sorry that was incorrect!");
        }else if (w.toLowerCase().equals("a")){
            System.out.println("Sorry that was incorrect!");
        }else{
            System.out.println("You pressed " +w+" Please choose A B or C"); 
        }
    } while (!correctAnswer);

然后，如果条件已经满足，代码块将不会执行

System.out.println("Second Question !!");
        System.out.println("What was the currency unit for Ireland before the Euro was introduced?");
        System.out.println("Is it\n\t\tA)Pound\n\t\tB)Dollar\n\t\tC)Punt\n");
        System.out.println("Please select A B or C");
        System.out.println("Your current score is " + score);
        String w;
        boolean guessed = false;
        do{
            w = scan.nextLine();
            if (w.toLowerCase().equals("c")) {
                System.out.println("Correct!");
                score = score + 1;
                System.out.println("Your new score is " + score);
                guessed = true;
            } else if (w.toLowerCase().equals("b")) {
                System.out.println("Sorry that was incorrect!");
                guessed = true;
            } else if (w.toLowerCase().equals("a")) {
                System.out.println("Sorry that was incorrect!");
                guessed = true;
            } else {
                System.out.println("You pressed " + w + " Please choose A B or C");
            }
        }while (!guessed);

---

您的代码将如下所示：

while (guessed){
    // your code goes here
}

    boolean correctAnswer = false;
    do {
        w = scan.nextLine();
        if (w.toLowerCase().equals("c")){
            score++; //same as score = score + 1;
            correctAnswer = true;
            System.out.println("Correct! Your new score is " +score);
        }else if (w.toLowerCase().equals("b")){
            System.out.println("Sorry that was incorrect!");
        }else if (w.toLowerCase().equals("a")){
            System.out.println("Sorry that was incorrect!");
        }else{
            System.out.println("You pressed " +w+" Please choose A B or C"); 
        }
    } while (!correctAnswer);

---

我现在知道，条件3，选择错误，已经得到满足，程序正在进行。我想知道如何强制它等待条件1或2。我建议您查看

Do While

循环以实现这一点。这是一个很好的答案，非常感谢。我希望困惑的阴霾最终会消散，我能开始擅长这些东西。感谢您花时间帮助一位新手。请注意-您需要将

w=scan.nextLine（）。。。对吧？：）呵呵，有点。。。你学的越多，你想解决的问题就越复杂，但这很有趣：）谢谢Micheal，不是每天我都能得到这么多支持，谢谢你帮助新来的家伙：）