Question

给出下面的第一个代码。创建Turtle类的正确方法是什么？ -基本上，我试图使它不显示错误：Turtle t = new Turtle(STARTX, STARTY, w);

我认为我的问题可能与重载构造函数有关：public Turtle (double STARTX, double STARTY, Class w )

import java.awt.*; //import color;

public class PA1{

  //These are constant values that you can use
  private static  final int STARTX = 100;
  private static  final int STARTY = 100;
  private static  final int CHAR_WIDTH = 100;
  private static  final int CHAR_HEIGHT = 100;
  private static  final int CHAR_SPACING = 50;

  public static void main(String[] args){

    //set the width and height of the world
    int width = 1000;
    int height = 1000;
    World w = new World(width, height);

    //create a turtle at the starting x and starting y pos
    Turtle t = new Turtle(STARTX, STARTY, w);

    //Set the turtle pen width.
    t.setPenWidth(15);

    //This is just an example. Feel free to use it as a reference. 
    //draw a T
    //Assume that the turtle always starts in the top left corner of the character. 
    t.turn(90); 
    t.forward(CHAR_WIDTH);
    t.backward(CHAR_WIDTH/2);
    t.turn(90);
    t.forward(CHAR_HEIGHT); 

    //Move the turtle to the next location for the character
    t.penUp();
    t.moveTo(STARTX+CHAR_WIDTH+CHAR_SPACING*1, STARTY);
    t.penDown(); 



    //WRITE YOUR CODE HERE

  }
}

我创建了2个新类：

public class World {
    //World w = new World(width, height);
    private double defaultWidth;
    private double defaultLength;

    public World () {
        defaultWidth = 0.0;
        defaultLength = 0.0; }

    public World (double width, double length){
        defaultWidth = width;
        defaultLength = length; }


    public double getWidth () {
        return defaultWidth; }


    public double getLength () {
        return defaultLength; }



    public void setWidth (double width){
        defaultWidth = width;   }


    public void setLength(double length){
        defaultLength = length; }



}

和

public class Turtle {

    // Turtle t = new Turtle(STARTX, STARTY, w);

    private double defaultSTARTX;
    private double defaultSTARTY;
    //private double defaultW;

    public Turtle ()    {
        defaultSTARTX = 0.0;
        defaultSTARTY = 0.0; 
        //defaultW = 0.0;
                        }

    public Turtle (double STARTX, double STARTY, Class w ){
        defaultSTARTX = STARTX;
        defaultSTARTY = STARTY; 
        //defaultW = w;
        }

    public double getSTARTX () {
        return defaultSTARTX; }


    public double getSTARTY () {
        return defaultSTARTY; }



    public void setSTARTX (double STARTX){
        defaultSTARTX = STARTX;         }


    public void setSTARTY(double STARTY){
        defaultSTARTY = STARTY;         }



}

Answer 1

如果您确实需要将World对象传递给Turtle对象，则应将Turtle构造函数定义为：

public Turtle (double STARTX, double STARTY, World w ){
    defaultSTARTX = STARTX;
    defaultSTARTY = STARTY; 
    defaultW = w;
}

另外，您必须声明“ w”不是像在某些时候所做的那样两倍，而是在Turtle中声明为“ World”类变量：

private World defaultW;

通过传递Class作为构造函数参数，您试图传递通用类定义，而不是任何类的Object实例。差异很细微，但确实存在，并且是您最有可能遇到的问题。

Answer 2

我在您上面提供的代码中发现了许多问题。我不知道这是否是完整的代码。我试图解决您代码中的所有问题-与您的构造函数和其他Java标准相关。以下为我工作-

Serializable

希望它可以解决您的查询。快乐的编码。：）

参数

2 个答案: