Question

我正在编写一个需要从.txt文件中取出一个单词的游戏/ java程序，然后将这些字母混淆并要求用户猜出它是什么单词。我有两个问题：

首先，我在运行时收到此错误消息：

Exception in thread "main" java.util.NoSuchElementException: No line found 
at java.util.Scanner.nextLine(Unknown Source) 
at Proj4.main(Proj4.java:20)

我遇到的第二个问题是喋喋不休。如果不使用shuffle命令（我不能使用），我无法弄清楚如何做到这一点。

这是我的代码：

import java.util.Scanner;
import java.util.Random;
import java.io.*;

public class Proj4 {

    public static void main(String[] args) throws IOException {
        Scanner inFile = new Scanner(new File ("words.txt"));

        int counter = 0;
        while (inFile.hasNext()) {
            inFile.nextLine();
            counter++;
        }

        String[] word = new String[counter];

        for (int j = 0; j < counter; j++) {
            word[j] = inFile.nextLine();
        }

        int lengthList = Integer.parseInt(word[0]);
        Scanner s = new Scanner(System.in);
        Random randomNumber = new Random();
        int i = randomNumber.nextInt(lengthList); //picks a word at random. assigns to "word"
        String currentWord = word[i];//picks a word at random. assigns to "currentWord"
        int turnScore = 10, finalScore = 0;
        char input;
        String guess ="a";

        do { //do loop for whole program looping
            turnScore = 10;
            do { //do loop for guessing correct                    
                do{
                    System.out.println("Current Puzzle: " + currentWord);
                    System.out.println("Current points for this word: " + turnScore);
                    System.out.println("Enter (g)uess, (n)ew word, (h)int, or (q)uit: ");
                    input = s.nextLine().charAt(0); //assigns input to first letter entered by user
                    Character.toLowerCase(input); //puts input to lower case
                    if(input != 'g' && input != 'G' && input != 'h' && 
                        input != 'H' && input != 'n' && input != 'N' && 
                        input != 'Q' && input != 'q'){
                        System.out.println("Invalid Entry. Please input g, n, q or h only! \n ");
                    }                        
                } while (input != 'g' && input != 'G' && input != 'h' && input != 'H' && 
                    input != 'n' && input != 'N' && input != 'Q' && input != 'q'); //end do while loop (ask for input)

                if (input == 'g') {
                    System.out.println("Enter Your guess: ");
                    guess = s.nextLine();
                    System.out.println("your guess is: " + guess + "\n\nThe word is: " + currentWord);

                    if (guess.equalsIgnoreCase(currentWord)) {
                        System.out.println("You Guessed Correct");
                        System.out.println("Your Score for this word is: " +turnScore );
                        finalScore =  finalScore + turnScore;
                    }//end if guess = currentWord
                    else
                    {                               
                        if (turnScore <= 0)
                        {
                            turnScore = 0;
                        }//end if turn score >=0
                        else 
                        {
                            turnScore -= 1;
                        }//end else turn score minus 1.

                        System.out.println("Nope, Sorry \n\n");
                    }//end else guess not = to currentWord.
                }//end if user input = G.                            
                else if (input == 'n')
                {
                    i = randomNumber.nextInt();
                    currentWord = word[i];
                    turnScore = 10;
                }//end new word if
                else if (input =='h')
                {
                    turnScore = turnScore/2;
                    Random ranNum = new Random();
                    int randomLetter = ranNum.nextInt(5);
                    char hint = currentWord.charAt(randomLetter);
                    System.out.println("the Letter at spot " + (randomLetter +1) + " is " + hint);
                }//end of if input = h
                else if (input == 'q')
                {
                    finalScore =  finalScore + turnScore;
                    System.out.println("Goodbye!");
                    System.out.println("Final Score: " + finalScore);
                    System.exit(0);
                }//end else if for input = Q.                               
            }while (!guess.equalsIgnoreCase(currentWord));                
        }while (input != 'q');

        System.out.println("Your Final Score is: " + finalScore);
        System.out.println("Goodbye!");
        inFile.close();
    }//End main 

}//end class

Answer 1

您的异常是由以下代码行引起的：

    int counter = 0;
    while (inFile.hasNext()) {
        inFile.nextLine();
        counter++;
    }

    //inFile no longer has next, will break when the for loop is entered

    String[] word = new String[counter];
    for (int j = 0; j < counter; j++) {
        word[j] = inFile.nextLine();
    }

解决这个问题的简单方法是重新声明inFile并重新开始阅读。

解决此问题的最佳方法是使用动态大小的ArrayList：

    int counter = 0;
    ArrayList<String> word = new ArrayList<String>();
    while (inFile.hasNext()) {
        word.add(inFile.nextLine());
        counter++;
    }

这也使你的随机化变得更容易，因为你可以做一些偷偷摸摸的事情。

以下是ArrayList的文档。

第二个问题的关键，而不是解决方案，是add(int index, E element)

当你阅读时，有一种方法可以随时随地播放。你应该弄清楚，如果你遇到困难，那就回来吧。

如何手动调整字符串中的字母

1 个答案: