Java猜数字项目代码多余空白行问题求助

问题根源 #

你的代码存在两处导致多余空白行的问题：

1. while循环内无条件输出空白行：不管当前是否输出了错误提示，循环都会执行System.out.println();，导致无错误场景下也会出现不必要的空白行。
2. 猜对后的多余换行：恭喜信息后添加的System.out.println();，会让后续评价语句前出现额外空白。

修改后的代码 #

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

public class GuessANumber {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a random seed: ");
        int seed = scanner.nextInt();
        Random rnd = new Random(seed);
        
        int rightAnswer = rnd.nextInt(200) + 1;
        
        int numAttempts = 0;
        
        System.out.print("Enter a guess between 1 and 200: ");
        int guess = scanner.nextInt();
        numAttempts++;
        
        while (guess != rightAnswer) {
            boolean hasError = false;
            if (guess < 1 || guess > 200) {
                System.out.println("Your guess is out of range. Pick a number between 1 and 200.");
                hasError = true;
            }
            if (guess > rightAnswer) {
                System.out.println("Your guess was too high - try again.");
                hasError = true;
            } else if (guess < rightAnswer) {
                System.out.println("Your guess was too low - try again.");
                hasError = true;
            }
            // 仅在输出错误提示后添加空白行
            if (hasError) {
                System.out.println();
            }
            System.out.print("Enter a guess between 1 and 200: ");
            guess = scanner.nextInt();
            numAttempts++;
        }
        
        if (guess == rightAnswer) {
            System.out.println("Congratulations!  Your guess was correct!");
            System.out.println("I had chosen " + rightAnswer + " as the target number.");
            System.out.println("You guessed it in " + numAttempts + " tries.");
        }
        
        if (numAttempts == 1) {
            System.out.println("That was impossible!");
        } else if (numAttempts == 2 || numAttempts == 3) {
            System.out.println("You're pretty lucky!");
        } else if (numAttempts >= 4 && numAttempts <= 7) {
            System.out.println("Not bad, not bad...");
        } else if (numAttempts == 8) {
            System.out.println("That was not very impressive.");
        } else if (numAttempts == 9 || numAttempts == 10) {
            System.out.println("Are you having any fun at all?");
        } else if (numAttempts >= 11) {
            System.out.println("Maybe you should play something else.");
        }
        
        scanner.close();
    }
}

修改说明 #

• 新增hasError布尔标志，仅当输出错误提示时才打印空白行，避免无提示场景下的多余换行。
• 移除恭喜信息后的独立空白行，消除评价语句前的额外空白。
• 调整代码缩进，让逻辑结构更清晰。

另外，你实际输出末尾的E属于测试时的输入异常，正常输入数字不会出现该问题。

内容的提问来源于stack exchange，提问作者John Obeto