java - 初始化从另一个类调用的值时，预计 token ";"、 、 出现语法错误

Question

我想在两个类之间传递一个值，但出现以下错误:

Syntax error on token ";", , expected when initializing called value from another class

我有初始值的类

public class Game extends Activity implements OnClickListener{

    RandomMathQuestionGenerator question = new RandomMathQuestionGenerator();
    private static final String TAG= "Sudoku";

    public static final String KEY_DIFFICULTY = 
            "org.example.sudoku.difficulty";
    public static final int DIFFICULTY_NOVICE = 1;
    public static final int DIFFICULTY_EASY = 2;
    public static final int DIFFICULTY_MEDIUM = 3;
    public static final int DIFFICULTY_GURU = 4;

    public int value = 0;

    private GameView gameView;  

    public Game()
    {
       if (KEY_DIFFICULTY == String.valueOf(1))
        {
            value = 2; 
        }
        else if (KEY_DIFFICULTY == String.valueOf(2))
        {
            value = 3;        
        }
        else if (KEY_DIFFICULTY == String.valueOf(3))
        {
            value = 4;
        }
        else if (KEY_DIFFICULTY == String.valueOf(4))
        {
            value = 6;
        }
    }

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate");    



    }
    @Override
    public void onClick(View v) 
    {           
          //code here       
    }
}

我调用值的类

public class RandomMathQuestionGenerator {

Game num = new Game();
int number = 0;
number = num.Game(value);
//public int number = 0;
//number = num.Game(number); 


private static final int NUMBER_OF_QUESTIONS = 1;
    private static final int MIN_QUESTION_ELEMENTS = 2;
    private final int MAX_QUESTION_ELEMENTS = number;
    private static final int MIN_QUESTION_ELEMENT_VALUE = 1;
    private static final int MAX_QUESTION_ELEMENT_VALUE = 100;
    private final Random randomGenerator = new Random();    

    //rest of irrelevant code below
    }

Answer 1

从长远来看，语法错误是无关紧要的。

在 Android 中，您必须启动带有 Intent 的 Activity。 (参见this Developer's Guide article。)当您想开始游戏时使用:

Intent intent = new Intent(this, Game.class);
startActivity(intent);

<小时/>

此外，您还将KEY_DIFFICULTY声明为final(不可更改):

public static final String KEY_DIFFICULTY = "org.example.sudoku.difficulty";

因此，在以下任何情况下，您的 if-else block 都不会为 true:

if (KEY_DIFFICULTY == String.valueOf(1))

并且要比较 Java 中的字符串，您必须使用 equals()，== 会给出不准确的结果。 (How do I compare strings in Java?)

<小时/>

如果您想将难度级别从一个 Activity 传递到另一个 Activity，请使用 Intent 的额外功能、public 类变量或以下位置中的其他方法:How do I pass data between Activities in Android application?

<小时/>

添加
您刚刚向您的问题添加了更多代码，并且您有循环逻辑。

- When you create RandomMathQuestionGenerator object, you will create a Game object
    - When you create Game object, you will create a RandomMathQuestionGenerator object
        - When you create RandomMathQuestionGenerator object, you will create a Game object
            - When you create Game object, you will create a RandomMathQuestionGenerator object
                - When you create RandomMathQuestionGenerator object, you will create a Game object
                    - When you create Game object, you will create a RandomMathQuestionGenerator object
                        - When you create RandomMathQuestionGenerator object, you will create a Game object
                            - When you create Game object, you will create a RandomMathQuestionGenerator object
                                - ...

只有当您的应用抛出 StackOverflowException 时，这才会停止。