如何將一種方法與另一種方法組合使用

Question

老實說，我不知道如何解決這個問題，這意味着當用戶在 class Player 的移動方法中輸入距離時，玩家 position 會相應移動。 我還希望 Jar 的 position 根據玩家移動的距離移動相同的量。

public class Player
{
    // instance variables - replace the example below with your own
    private String name;
    private int position;
    private Jar jar;

    public Player()
    {
        position = 0;
        jar = new Jar();

        System.out.print("Enter player's name: ");
        this.name = Global.keyboard.nextLine();

    }

    public int move(int distance)
    {
        position = position + distance;
    }
}


public class Jar
{
    private int position;
    private Stone stone;


    public Jar()
    {
        position = 0;
        stone = null;
    }

    public Jar(int initPos, Stone stone)
    {
        position = initPos;
        this.stone = stone;
    }

     public void move()
    {
        Player move = new Player();
    }
}

Answer 1

您可以在Player中修改Jar position 。 此外，您可能不想每次更改 position 時都創建新Player 。

public class Player {

    ...

    public int move(int distance) {
        position = position + distance;
        jar.move(distance);
    }
}


public class Jar {
    private int position;
    private Stone stone;

    public Jar() {
        position = 0;
        stone = null;
    }

    public Jar(int initPos, Stone stone) {
        position = initPos;
        this.stone = stone;
    }

     public void move(int distance) {
        position += distance;
    }
}

Answer 2

我已將方法更改為 void，因為當 move 方法獲取距離值時，沒有理由返回值。 它還將更改 Player class 實例的 position 實例它將調用 Jar 實例移動方法。 When Jar Class Instance move method is called then jar position also be changed Look at the Jar Move method

public class Player
{
    // instance variables - replace the example below with your own
    private String name;
    private int position;
    private Jar jar;

    public Player()
    {
        position = 0;
        jar = new Jar();

        System.out.print("Enter player's name: ");
        this.name = Global.keyboard.nextLine();

    }

    public void move(int distance)
    {
        position = position + distance;
        jar.move(distance); 
    }
}


public class Jar
{
    private int position;
    private Stone stone;


    public Jar()
    {
        position = 0;
        stone = null;
    }

    public Jar(int initPos, Stone stone)
    {
        position = initPos;
        this.stone = stone;
    }

     public void move( int distance)
    {
       position = position+distance;
    }
}
```