java - 如何重复整个程序直到手动终止？

Question

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已关闭 9 年前。

我的代码工作正常，除了我应该询问用户是否要退出程序的部分。这是一个简单的 y/n，如果输入“n”，则应触发整个程序重复，并在输入“y”时终止。我知道我需要使用 while 循环，但我只是无法弄清楚我需要如何在代码中编写它，以便它按预期工作。

import java.util.*;

public class MilitaryTime 

{

public static void main (String [] args)    
{

            Scanner in = new Scanner(System.in);
            int hour1, minute1, hour2, minute2;

            System.out.print("Please enter the first time: ");
            int time1 = in.nextInt();
            System.out.println();
            hour1 = time1 / 100;
            minute1 = time1 % 100;

            System.out.print("Please enter the second time: ");
            int time2 = in.nextInt();
            System.out.println();
            hour2 = time2 / 100;
            minute2 = time2 % 100;

            System.out.println("Time elapsed: " + (Math.abs(hour1 - hour2) + " Hours, " + (Math.abs(minute1 - minute2) + " Minutes \n")));

            System.out.print("Do you want to quit? (y/n): ");
            String answer = in.next();

            while (answer != "n")
            {

            }

    }

}

Answer 1

您可能应该将代码拆分为(至少)两种不同的方法，但我只是尝试指出一种通过最少的更改来实现您想要的效果的方法:

public static void main (String [] args)    
{
    String answer = null;  // you have no answer yet...
    do {   // ... but you want to execute your stuff at least once
        Scanner in = new Scanner(System.in);
        int hour1, minute1, hour2, minute2;

        System.out.print("Please enter the first time: ");
        int time1 = in.nextInt();
        System.out.println();
        hour1 = time1 / 100;
        minute1 = time1 % 100;

        System.out.print("Please enter the second time: ");
        int time2 = in.nextInt();
        System.out.println();
        hour2 = time2 / 100;
        minute2 = time2 % 100;

        System.out.println("Time elapsed: " + (Math.abs(hour1 - hour2) + " Hours, " + (Math.abs(minute1 - minute2) + " Minutes \n")));

        System.out.print("Do you want to quit? (y/n): ");
        answer = in.next();
    } while (!answer.equalsIgnoreCase("n"));

}