java - 简单的Java方法？

Question

好吧，我需要用java编写一个程序，它基本上是一个随机数生成器，玩家需要猜测生成了什么数字，从1到10。

我已经获得了代码，一切都工作得很好(代码发布在下面)，但我想让用户不能两次使用相同的号码。

例如，玩家输入 2，然后输入 3，然后再次输入 2。我想要它 return “您已经输入了这个号码” 对于我的一生，我无法让它发挥作用。

我一直在尝试使用 HashSets，因为我相当确定该方法是正确的方法，但是当涉及到调用 HashSet 中已有的数字以及它们是否在HashSet 已经返回“您已经输入了这个数字”。

我尝试修改

if (hs.contains(guess)) == true) 
System.out.println("You have already entered this number")

我还输入了hs.add(guess)并猜测玩家输入的数字。我真的很困惑，如果你们能引导我走向正确的方向，我将不胜感激。 非常感谢高级

package guessgame;

import java.util.HashSet;
import java.util.Scanner;

public class GuessGame {

    public static void main(String[] args) {

        HashSet<Integer>hs = new HashSet();
        int GuessLogic;
        GuessLogic = (int) (Math.random() * 10 + 1);
        Scanner keyboard = new Scanner (System.in);
        int guess;
        int NumGuess;
        NumGuess = 1;

        do {
            System.out.print("Enter a guess: ");
            guess = keyboard.nextInt();
            System.out.println("Your guess is " + guess);
            if (guess == GuessLogic)
                System.out.println("You got it right!! Congrats!! Total Number of Guesses: " + NumGuess++);
            else if (guess < GuessLogic && guess > 0)
                System.out.println("You are wrong!!! Hint: Guess Higher, Guess number: " + NumGuess++);
            else if (guess > GuessLogic && guess <= 10)
                System.out.println("You are wrong!!! Hint: Guess Lower, Guess number: " + NumGuess++); 
            else
                System.out.println("Your guess is out of the specified range. Please try again." ); 
        } while (guess != GuessLogic);

    }   

} 

Answer 1

首先，您应该对接口(interface)进行编程 Set (而不是具体类型HashSet)。接下来，您可以使用Set.add(E)如果此集合尚未包含指定元素，则返回true。。最后，我建议使用有意义的变量名称。把它们放在一起，它可能看起来像，

Set<Integer> hs = new HashSet<>();
int correctNumber = 1 + (int) (Math.random() * 10);
Scanner keyboard = new Scanner(System.in);
int guessCount = 1;
int guess;
do {
    System.out.print("Enter a guess: ");
    guess = keyboard.nextInt();
    System.out.println("Your guess is " + guess);
    if (hs.add(guess)) {
        if (guess == correctNumber) {
            System.out.println("You got it right!! Congrats!! Total Number of "
                    + "Guesses: " + guessCount++);
        } else if (guess < correctNumber && guess > 0) {
            System.out.println("You are wrong!!! Hint: Guess "
                    + "Higher, Guess number: " + guessCount++);
        } else if (guess > correctNumber && guess <= 10) {
            System.out.println("You are wrong!!! Hint: Guess "
                    + "Lower, Guess number: " + guessCount++);
        } else {
            System.out.println("Your guess is out of the specified range. "
                    + "Please try again.");
        }
    } else {
        System.out.println("You have already entered this number");
    }
} while (guess != correctNumber);