Question

这是我的代码，该程序是一个简单的猜数字游戏，其中计算机选择一个介于1和x之间的随机数（在程序内设置），用户将使用计算机的反馈来猜测该数字，说明是否每个猜测都高于或低于秘密数字。

代码由4种方法组成，这是一种主要方法，其中在显示播放指令后声明几个变量。然后设置while循环以开始新游戏。在while循环的3行中，调用了一种方法来开始玩新游戏，同时传递了扫描仪/控制台和一个名为guess的整数（每次调用此方法时设置为0）。

这个整数，每当用户进行一次猜测时，就会增加1，应该在游戏方法的结尾处返回，但是我似乎无法弄清楚为什么不返回。需要将其返回，以便可以将其传递给results方法，以计算如果用户决定不再玩游戏将显示的统计信息。

任何帮助将不胜感激...

import java.util.*;
public class Guess {
   public static void main(String[] Args) {
      Scanner console = new Scanner(System.in);
      Introduction(); //required
      int games = 0;
      int newGame = 1;
      int guesses = 0;
      int maxguesses = 0;
      int totalguesses = 0;
      while (newGame == 1) {
         String userNewGame = "";
         games = games + 1;
         Game(guesses,console); //required
         if (guesses > maxguesses) {
            guesses = maxguesses;
         }
         totalguesses = totalguesses + guesses;
         System.out.print("Do you want to play again? ");
         userNewGame = console.next();
         System.out.println();
         char first = userNewGame.charAt(0);
         if ( first == 'Y' || first == 'y') {
            newGame = 1;
         }
         else if ( first == 'N' || first == 'n') {
            newGame = 0;
         }
      }
      Results(games,totalguesses,maxguesses); //required
   }
   public static void Introduction() {
      System.out.println("This program allows you to play a guessing game.");
      System.out.println("I will think of a number between 1 and 100");
      System.out.println("and will allow you to guess until you get it.");
      System.out.println("For each guess, I will tell you whether the");
      System.out.println("right answer is higher or lower than your guess.");
      System.out.println();
   }
   public static int Game(int guesses, Scanner console) {
      Random rand = new Random();
      int range = 100; //Change this value to set the range the computer will require to guess ie. 100 is 1 to 100 inclusive, 5 is 1 to 5 inclusive, etc.
      int number = rand.nextInt(range) + 1;
      guesses = 0;
      int guess = -1;
      System.out.println("I'm thinking of a number...");
      while (guess != number) {
         System.out.print("Your guess? ");
         guess = console.nextInt();
         guesses = guesses + 1;
         if (guess < number) {
            System.out.println("higher");
         }
         if (guess > number) {
            System.out.println("lower");
         }
         if (guess == number) {
            System.out.println("You got it right in " + guesses + " guesses");
            System.out.println();
         }
      }
      return guesses;
   }
   public static void Results(int games,int totalguesses,int maxguesses) {
      System.out.println("Overall results:");
      System.out.println("    total games   = " + games);
      System.out.println("    total guesses = " + totalguesses);
      System.out.println("    guesses/game  = " + totalguesses / games);
      System.out.println("    max guesses   = " + maxguesses);
   }
}

Answer 1

这里发生了很多事情，并且所有这些都是相互依存的。

您没有捕获从Game返回的值的结果。
您正在使用变量做一些非常奇怪的事情，这降低了可读性。
在遍历此程序时，Scanner会遇到问题。

让我们从低落的果实开始。 Game返回一个int，但未在任何地方分配。理想情况下，应将其分配给guesses的值。

guesses = Game(guesses,console); //required

...除了在以下情况下传递guesses并没有实际意义：

我们主要对其进行重新分配（不用担心，由于Java是pass by value，因此Game方法将拥有自己的猜测副本）
您将其明确分配给Game中的0 无论如何

因此，您想将其作为方法的参数删除。

guesses = Game(console);

在Game内，您可以定义自己的guesses变量。

public static int Game(Scanner console) {
    Random rand = new Random();
    int range = 100; //Change this value to set the range the computer will require to guess ie. 100 is 1 to 100 inclusive, 5 is 1 to 5 inclusive, etc.
    int number = rand.nextInt(range) + 1;
    int guesses = 0;
    int guess = -1;
    System.out.println("I'm thinking of a number...");
    while (guess != number) {
        System.out.print("Your guess? ");
        guess = console.nextInt();
        guesses = guesses + 1;
        if (guess < number) {
            System.out.println("higher");
        }
        if (guess > number) {
            System.out.println("lower");
        }
        if (guess == number) {
            System.out.println("You got it right in " + guesses + " guesses");
            System.out.println();
        }
    }
    return guesses;
}

我可以看到的最后一个明显的问题是您正在使用next()的地方，但是您并没有为Scanner清除缓冲区。

userNewGame = console.next();
// and inside of Game()
guess = console.nextInt();

This is a surprisingly common Scanner problem，并且很容易解决。

userNewGame = console.next();
console.nextLine();
// and inside of Game()
guess = console.nextInt();
console.nextLine();

或者，您可以改用nextLine而不处理next()，因为它们都返回String。区别在于next()不使用Return / Enter生成的换行符，而nextLine() 这样做。

Answer 2

您应该使用返回的值更新变量，而不是仅调用Guesses方法，如下所示：

guesses = Game(guesses,console); //required

如果要让最大猜测者（在所有游戏中）保持最大猜想，那么应该在调用Game方法之后更新逻辑，

     if (guesses > maxguesses) {
        maxguesses = guesses; // not guesses = maxguesses
     }

这是我发布的整个代码，我认为效果很好。检查一下：

    import java.util.*;
public class Guess {
   public static void main(String[] Args) {
      Scanner console = new Scanner(System.in);
      Introduction(); //required
      int games = 0;
      int newGame = 1;
      int guesses = 0;
      int maxguesses = 0;
      int totalguesses = 0;
      while (newGame == 1) {
         String userNewGame = "";
         games = games + 1;
         guesses = Game(guesses,console); //required
         if (guesses > maxguesses) {
            maxguesses = guesses;
         }
         totalguesses = totalguesses + guesses;
         System.out.print("Do you want to play again? ");
         userNewGame = console.next();
         System.out.println();
         char first = userNewGame.charAt(0);
         if ( first == 'Y' || first == 'y') {
            newGame = 1;
         }
         else if ( first == 'N' || first == 'n') {
            newGame = 0;
         }
      }
      Results(games,totalguesses,maxguesses); //required
   }
   public static void Introduction() {
      System.out.println("This program allows you to play a guessing game.");
      System.out.println("I will think of a number between 1 and 100");
      System.out.println("and will allow you to guess until you get it.");
      System.out.println("For each guess, I will tell you whether the");
      System.out.println("right answer is higher or lower than your guess.");
      System.out.println();
   }
   public static int Game(int guesses, Scanner console) {
      Random rand = new Random();
      int range = 100; //Change this value to set the range the computer will require to guess ie. 100 is 1 to 100 inclusive, 5 is 1 to 5 inclusive, etc.
      int number = rand.nextInt(range) + 1;
      guesses = 0;
      int guess = -1;
      System.out.println("I'm thinking of a number...");
      while (guess != number) {
         System.out.print("Your guess? ");
         guess = console.nextInt();
         guesses = guesses + 1;
         if (guess < number) {
            System.out.println("higher");
         }
         if (guess > number) {
            System.out.println("lower");
         }
         if (guess == number) {
            System.out.println("You got it right in " + guesses + " guesses");
            System.out.println();
         }
      }
      return guesses;
   }
   public static void Results(int games,int totalguesses,int maxguesses) {
      System.out.println("Overall results:");
      System.out.println("    total games   = " + games);
      System.out.println("    total guesses = " + totalguesses);
      System.out.println("    guesses/game  = " + totalguesses / games);
      System.out.println("    max guesses   = " + maxguesses);
   }
}

示例输出：

    This program allows you to play a guessing game.
I will think of a number between 1 and 100
and will allow you to guess until you get it.
For each guess, I will tell you whether the
right answer is higher or lower than your guess.

I'm thinking of a number...
Your guess? 10
higher
Your guess? 50
lower
Your guess? 40
lower
Your guess? 30
lower
Your guess? 20
lower
Your guess? 15
You got it right in 6 guesses

Do you want to play again? y

I'm thinking of a number...
Your guess? 50
higher
Your guess? 80
higher
Your guess? 90
lower
Your guess? 85
You got it right in 4 guesses

Do you want to play again? n

Overall results:
    total games   = 2
    total guesses = 10
    guesses/game  = 5
    max guesses   = 6

如何正确传递变量？

2 个答案: