java - 如何在Java中使用if有条件地循环语句？

Question

我刚刚开始在类里面学习 Java。作业是制作一个石头剪刀布游戏，这是我的源代码。我已经上交了，但还没有收到成绩。

package rockpaperscissors;

import java.util.Random;
import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    // Create scanner input
    Scanner input = new Scanner (System.in);

    // Introduce user to game
    System.out.println("Welcome to the Rock, Paper and Scissors game");

    // Ask the user for their move
    System.out.println("\nPlease select a move\nEnter 0 for Scissors, 1 "
            + "for Rock and 2 for Paper");
    int userMove = input.nextInt();

    // Ensure that userMove is between 0 and 2
    if (userMove > 2 || userMove < 0) {
        System.out.println("Invalid entry the result of this game will not "
                + "be accurate! Please retry using either 0 for Scissors, 1"
                + " for Rock and 2 for Paper\n");
    }

    // Generate computerMove using java.util.Random
        // Create instance first
    Random MyRandom = new Random();

    //Now generate number
    int computerMove = MyRandom.nextInt(3);

    System.out.print("The computer played " + computerMove + "\nRemember"
            + " 0 stands for Scissors, 1 is for Rock and 2 is for paper\n");

    // Determine draw result
    if (userMove == computerMove) {
        System.out.println("\nYou played " + userMove + ", The computer "
                + "played " + computerMove + " The game is a draw!");
    }
    // Determine computer win
    else if(userMove == 0 && computerMove == 1) {
        System.out.println("\nYou played " + userMove + ", The computer "
                + "played " + computerMove + " The Computer Wins!");


    }

    else if(userMove == 2 && computerMove == 0) {
        System.out.println("\nYou played " + userMove + ", The computer "
                + "played " + computerMove + " The Computer Wins!");

    }

    else if(userMove == 1 && computerMove == 2) {
        System.out.println("\nYou played " + userMove + ", The computer "
                + "played " + computerMove + " The Computer Wins!");

    }

    /* Determine User win, as no other moves can result in computer win all
    other combinations will result in user win
     */

            else {
        System.out.print("\nYou played " + userMove + ", The computer "
                + "played " + computerMove + " You Win!");
    }



}

}

如果数字大于 2 或小于 0，我无法让程序重新请求数字，它会显示“无效输入，结果将无效...”，但它仍会执行程序的其余部分具有无效编号。

如何让程序停止并提示用户输入有效号码，然后执行程序？此外，这是我制作的第三个程序，因此任何其他建议将不胜感激。

谢谢

Answer 1

如果满足您的条件，您想要的是不执行所有其他代码。

现在，当满足您的条件时，您会给出错误消息 - 但不会停止函数其余部分的执行。

你可以停下来。

那么 - 在不告诉你确切答案的情况下...如何退出函数？在显示错误消息后立即执行此操作，就可以了。

但是 - 如果您想继续获取用户输入直到满足条件...这需要围绕获取和检查的部分进行循环。

你知道什么循环？

你知道有一个可以让你循环直到满足某些条件吗？

你已经有了你的条件...现在你只需要调整一个循环来让你重复执行你想要的代码，直到满足该条件。

伪代码(即这不是真正的java - 你必须翻译):

some_loop do
   fetch user input
   give error message if its not ok
until (user input is ok)