方法 x 对于类型 y 是未知的

Question

So I am trying to get a random word from a list of words in a Class called Lexicon.

public abstract class Lexicon {

public String getWord(int index) {
    switch (index) {
        case 0: return "UNIVERSITY";
        case 1: return "COMPUTER";
        case 2: return "LAPTOP";
        case 3: return "HEADPHONES";
        case 4: return "FUZZY";
        case 5: return "HOTEL";
        case 6: return "KEYHOLE";
        case 7: return "TELEPHONE";
        case 8: return "PRINTER";
        case 9: return "BUILDING";
        default: return "Illegal index";
        }

    }; 

}

To a class called Game :

import java.util.Random;

public class Game {
    private int MaxGuess;
    private boolean GameOver;
    private String RandomWord;

    public Game(int maxGuess, boolean gameOver, Lexicon randomWord) {
        super();
        MaxGuess = maxGuess;
        GameOver = gameOver;

        Random rand = new Random();

        int  n = rand.nextInt(9);
        RandomWord=getWord(n);


    }

    public void Result(boolean GameOver) {
        if(GameOver) {
            System.out.println("You have won the game!!");
        }
        else {
            System.out.println("You Lost!!");
        }
    }



}

and I get an error that says Method getWord(int) is unidentified for type Game. It must be something really simple but I cannot get myself to find the mistake. Been trying for like an hour.My java skills got rusty through out Summer. Any help would be appreciated.Thank you in advance.

Answer 1

因为getWord()是在Lexicon类中定义的，而不是在Game类中定义的。

Answer 2

You need game to extend Lexicon if you wish it to inherit the functions

public class Game extends Lexicon {
    ...
}

Or use the Lexicon you have:

RandomWord=randomWord.getWord(n);

Answer 3

The function getWord is in a different class. You can either copy the method into the game class or try to call Lexicon.getWord() instead

Answer 4

Well, you should do RandomWord = randomWord.getWord(n) , not just RandomWord=getWord(n) .

In any case it is not clear to my why you do it in this way. The lexicon can be just a list of strings instead of a switch statements hidden inside a class (and an abstract one!)

Answer 5

Two problems are needed to be addressed,

1. The nextInt function will never get 0-9, but 0-8, please changed this line

   int n = rand.nextInt(9);

   to

   int n = rand.nextInt(10);

2. The getWord() is not defined in Game Class. You should be calling from the Lexicon Class. And i recommend you to change it to static. which is changed from

   public String getWord(int index) {

   to

   public static String getWord(int index) {

   So you can call the function directly with

   RandomWord = Lexicon.getWord(n);

   In this way, you saved performance and also have the proper way to implement a function as static logic should always be implemented this way.

---

*Remark: not related to compiling or bugs, but for you variable naming:

private int MaxGuess;
private boolean GameOver;
private String RandomWord;

unless you should always begin with small letter following smallCamelToe convention, some examples are as follow:

//variable
private int maxGuess;
private boolean gameOver;
private String randomWord;

//constant variable
private final int MAX_GUESS = 1;

//static constant variable, usually be used when implementing constant files and import from other classes
public static final boolean GAME_OVER;

and it is ok to implement the following:

public Game(int maxGuess, boolean gameOver) {
    super();
    maxGuess = maxGuess; //you can use this.maxGuess if compile failed
    gameOver = gameOver; //you can use this.gameOver if compile failed

    Random rand = new Random();
    RandomWord = Lexicon.getWord(rand.nextInt(9));
}