Question

我是一名新的程序员，并试图通过随机项目来教自己Java。下面是一个“Rock，Paper，Scissors”游戏，我面临的问题是在打印“a”之后，程序结束并且不会继续下面的if else语句。我们将非常感谢您提供的任何帮助。

package com.company;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        System.out.println("Hello & Welcome to Rock, Paper, Scissors. What's your name?");
        Scanner scan = new Scanner(System.in);
        String userChoice = scan.nextLine();
        System.out.println("Hello, " + userChoice + ". Let's start a game!");
        Scanner scan = new Scanner(System.in);
        System.out.println("Choose one: Rock, Paper, Scissors");
        String userFirstChoice = scan.nextLine();
        System.out.println("You chose " + userFirstChoice);

        double a = Math.random();
        System.out.println(a);



        if (a >= 0.00 && a<= 0.3){
            if ( userFirstChoice== "Rock"){
                System.out.println("Rock vs Rock: TIE");
            }
            else if (userFirstChoice == "Paper"){
                System.out.println("Rock vs Paper: YOU LOSE!");
            }
            else if (userFirstChoice == "Scissors"){
                System.out.println("Rock vs Scissors: YOU WIN!");
            }

        }
        else if (a>=0.3 && a<=0.6){
            if(userFirstChoice == "Paper"){
                System.out.println("Paper vs Paper: TIE!");
            }
            else if (userFirstChoice == "Rock"){
                System.out.println("Rock vs Paper: YOU LOSE!");
            }
            else if(userFirstChoice == "Scissors"){
                System.out.println("Scissors vs Paper: YOU WIN!");
            }

        }
        else if (userFirstChoice == "Scissors"){
            System.out.println("Scissors vs Scissors: TIE!");
        }
        else if (userFirstChoice == "Paper"){
            System.out.println("Paper vs Scissors: YOU LOSE!");
        }
        else if (userFirstChoice == "Rock") {

            System.out.println("Rock vs Scissors: YOU WIN!");
        }

    }


}

Answer 1

您无法使用==来比较Java中的字符串。（==比较引用，而==的操作数可能是对不同字符串的引用，即使字符串 contents 相同。）

请改用userFirstChoice.equals("Scissors")等。

您对double类型上的关系运算符的使用是正确的。

为什么我的代码不能打印math.random？

1 个答案: