Question

我正在学习自己使用Java和代码，我是网络技术，并想学习如何编码。我正在从一个名为编程的网站上学习，我被困在一项任务上：

https://programmingbydoing.com/a/twenty-questions.html

下面是我的代码，它会编译，但问题是嵌套if语句不能正常工作请帮助!!!

import java.util.Scanner;
public class twentyQuestions 
    {
    public static void main(String[] args)
        {
        Scanner keyboard = new Scanner(System.in);
        String question1, question2, guess;

        System.out.println("TWO QUESTIONS!");
        System.out.println("Think of an object, and I will try to guess it.");
        System.out.println();

        System.out.println("Question 1: Is it an animal, vegetable, or mineral?");
        question1 = keyboard.next();

        System.out.println();

        System.out.println("Question 2: Is it bigger than a bread box?");
        question2 = keyboard.next();


        if (question1.equals("animal"))

        {
                if (question2.equals("no"))

                {
                    guess = "squirrel";
                }
                else {
                    guess = "moose";
                }
        }


        else if (question1.equals("vegetable"))

            {
            if (question2.equals("no"))
            {
                guess = "carrot";
            }
            else 
            {
                guess = "watermelon";
            }
            }


        else if (question1.equals("mineral"));


        {
            if (question2.equals("no"))
            {
                guess = "paper clip";
            }
            else 
            {
                guess = "Camaro";
            }

        }

        System.out.println("You're thinking of a " + guess);
        }

    } 
}

Answer 1

首先，您需要在

之后删除分号

else if (question1.equals("mineral"))

然后，您需要在else语句的末尾添加最后的if块，以捕获与三个输入中的任何一个都不匹配的输入。然后它就可以编译：

    ...
    else if (question1.equals("mineral"))

    {
        if (question2.equals("no")) {
            guess = "paper clip";
        } else {
            guess = "Camaro";
        }

    }else{
        System.out.println("Invalid input");
        return;
    }
    ...

Answer 2

谢谢你们这里是我最后的代码，感谢所有人......： import java.util.Scanner;

公共课二十问题 { public static void main（String [] args） { 扫描仪键盘=新扫描仪（System.in）; 字符串question1，question2，guess =“”;

    System.out.println("TWO QUESTIONS!");
    System.out.println("Think of an object, and I will try to guess it.");
    System.out.println();

    System.out.println("Question 1: Is it an animal, vegetable, or mineral?");
    question1 = keyboard.next();

    System.out.println();

    System.out.println("Question 2: Is it bigger than a bread box?");
    question2 = keyboard.next();


    if (question1.equals("animal"))

    {
            if (question2.equals("no"))

            {
                guess = "squirrel";
            }
            else {
                guess = "moose";
            }
    }


    else if (question1.equals("vegetable"))

        {
        if (question2.equals("no"))
        {
            guess = "carrot";
        }
        else 
        {
            guess = "watermelon";
        }
        }


    else if (question1.equals("mineral"))


    {
        if (question2.equals("no"))
        {
            guess = "paper clip";
        }
        else 
        {
            guess = "Camaro";
        }

    }

      else{
    System.out.println("Invalid input");
    return;
    }

    System.out.println("You're thinking of a " + guess);
    }

}

新手嵌套if语句

2 个答案: