java - 正确的代码无法编译？

Question

这段代码对我来说似乎完全没问题(CS101)，但我的 IDE 抛出错误“此方法必须返回 boolean 类型的结果”

我不需要任何有关如何简化代码或类似内容的提示，只是想要一个原因/解决方案来说明为什么会发生这种情况

public static boolean validation(String correct1, String correct2)
{
   Scanner in = new Scanner(System.in);

    boolean correctInput = false;
    String userInput;

    while (correctInput == false)
    {
        System.out.print("Type in " + correct1 + " or " + correct2);
        userInput = in.next();

        if ( userInput.equals(correct1) )
        {
            return true;
        }else if ( userInput.equals(correct2) )
        {
            return false;
        }else
        {
            System.out.println("Try again!");
        }
    }   
}

问题现已解决，任何人有兴趣为什么我需要下面的完整代码:

import java.util.*;
public class CheckingInput
{
public static void main(String args[])
{
    System.out.println("What is 1+1?");
    boolean answer = validation("two", "three");
    if(answer == true)
    {
        System.out.print("Correct!");
    }else if(answer == false)
    {
        System.out.print("Wrong!");
    }
}

public static boolean validation(String correct1, String correct2)
{
    Scanner in = new Scanner(System.in);
    boolean correctInput = false;
    String userInput;

    while (correctInput == false)
    {
        System.out.print("Type in " + correct1 + " or " + correct2 + ": ");
        userInput = in.next();

        if ( userInput.equals(correct1) )
        {
            correctInput = true;
            return true;

        }else if (userInput.equals(correct2))
        {
            correctInput = true;
            return false;
        }else
        {
            System.out.println("Try again!");
            correctInput = false;
        }
    }   
    return false;// Doesn't really matter, loop will never reach here
}

Answer 1

我假设无限循环是故意的，因为您正在等待用户的响应，因此请尝试以下操作:

public static boolean validation(String correct1, String correct2)
{
    Scanner in = new Scanner(System.in);
    String userInput;

    while (true)
    {
        System.out.print("Type in " + correct1 + " or " + correct2);
        userInput = in.next();

        if ( userInput.equals(correct1) )
        {
            return true;
        }
        else if ( userInput.equals(correct2) )
        {
            return false;
        }
        else
        {
            System.out.println("Try again!");
        }
    }

    return false; // Doesn't really matter, loop will never reach here
}