Question

我开始学习Java已经3个月了。

我对Java很陌生。

作为课程工作的一部分，我获得了使用instantiable课程开发Hangman游戏的Java源代码的课堂作业。所有人都使用Filereaders来读取用户的输入，但我尝试使用Scanner类来解决它，以使其更简单直接。

但我得到的错误是＆＃34;类接口或枚举预期＆＃34;。我尝试过多次编辑代码，但没有用。请告诉我我做错了什么。

预期的输出是让玩家知道他每次输入新信时都会显示他的生活，猜测和其他统计数据。

谢谢。

这是我的代码：

主要课程

import java.util.Scanner;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;

public class Main {

    int lives = 7;
    Scanner sc = new Scanner(System.in);

    public static void main(String args[]) {

        String name = "", response = "y";

        HangmanApp appobj = new HangmanApp();

        System.out.println("Please Enter your name: ");

        int games_played = 0, games_won = 0, games_lost = 0;

        name = sc.nextLine();

        while ((response.equalsIgnoreCase("y")) || (response.equalsIgnoreCase("yes"))) {
            games_played++;

            if (appobj.runme(randInt()) ) {
                System.out.println("Congrats " + name + " you have won this game!");
                games_won++;
            } else {
                System.out.println("Sorry " + name + " you have lost this game!");
                games_lost++;
            }
            System.out.println("Do you want to play again? Type y or n ");
            response = sc.nextLine();
        }

        // provide statistics after user says no to continue
        System.out.println("Game Statistics-");
        System.out.println("Game played:" + games_played);
        System.out.println("Game won: " + games_won);
        System.out.println("Game lost: " + games_lost);

    }

    public static int randInt() {
        Random rand = new Random();
        int randomNum = rand.nextInt(5) + 1;
        return randomNum;
    }
}

可实例化的课程 - #HangmanApp

import java.util.Scanner;
import java.util.ArrayList;

public class HangmanApp {
    String word_list[] = { "programming", "exhaustive", "violin", "selection",           "repetition", "serendipity",
                            "alabama", "alaska", "arizona", "arkansas", "california", "colorado",
                             "connecticut", "delaware", "florida", "georgia", "hawaii", "idaho",
                              "illinois", "indiana", "iowa", "kansas", "kentucky", "louisiana",
                                "maine", "maryland", "massachusetts", "michigan", "minnesota", "mississippi" };

    Scanner scan = new Scanner(System.in));

    public boolean runme(int index) {

        String correct_word = word_list[index].toString();
        //System.out.println("Word: " + correct_word);
        int corr_wrd_count = correct_word.length();
        int left_lives = 7;

        ArrayList<String> letter_chosen = new ArrayList<String>();
        ArrayList<String> hangman = new ArrayList<String>();

    try {
        // Insert blank chars
        for(int i =0; i < corr_wrd_count; i++)
        {
            hangman.add("_");
        }

        while (left_lives != 0 ) {
            System.out.print("Guess a letter: ");
            try {
                String letter_entered = scan.nextLine().toLowerCase();

                if (letter_entered.length() == 1) {
                    if(! isNumeric(letter_entered)) {
                        if (letter_chosen.contains(letter_entered)) {
                            System.out.println("You have already entered this character. Try another.");
                        }
                        else {
                            letter_chosen.add(letter_entered);
                            if (correct_word.contains(letter_entered)) {
                                // Insert the char at all instances of the string
                                for (int i = -1; (i = correct_word.indexOf(letter_entered, i + 1)) != -1; ) {
                                    hangman.set(i, letter_entered);
                                }
                            }
                            else {
                                // Lost life
                                left_lives--;
                            }
                        }

                        // print status
                        System.out.println("------------------------");
                        System.out.println("Lives: " + left_lives);
                        System.out.println("Word: " + String.join(" ", hangman));
                        System.out.println("Letters chosen so far: " + letter_chosen);

                        // Check if array has any pending -
                        if (! hangman.contains("_")) {
                            return true;
                        }
                    }
                    else {
                        System.out.println("Buddy this is Hangman not betting... Try entering letter ->");
                    }
                }
                else {
                    System.out.println("Please be patient and enter only 1 letter...");
                }
            }
                return false;
            }

        } // end while

    }
        return false;
    }
    return false;
}

public static boolean isNumeric(String str)
{
      double d = Double.parseDouble(str);

    {
      return false;
    }
    return true;
  }

}

Answer 1

你的isNumeric方法很可疑

{
  double d = Double.parseDouble(str);

{
  return false;
}
return true;

}

你回归真假吗？这可能是导致错误的原因。你有太多的花括号关闭。正确缩进代码并检查您是否正确打开和关闭大括号。

此外，在Main类中，您有两个非静态变量，因此无法从静态main方法访问它们。

Answer 2

没有编译它，但我可以在Main类

中看到一些错误

声明扫描仪在public static void main(String[] str){ }之外，然后在里面使用它会在你静态引用非静态字段时给出错误

这就像在静态方法中调用实例方法和字段一样，这是无法完成的，因为实例字段和方法在没有对象的情况下不存在，而在main方法内部则没有此对象。您必须改为创建该类的实例，然后调用该实例上的方法。

public class Main {

int lives = 7;
Scanner sc = new Scanner(System.in);//this sc can't be called inside main
public static void main(String args[]) {

    String name = "", response = "y";

    HangmanApp appobj = new HangmanApp();

    System.out.println("Please Enter your name: ");

    int games_played = 0, games_won = 0, games_lost = 0;
    name = sc.nextLine();

编译Hangman游戏

2 个答案: