1

如果我在类 Point 中有一个名为 Point 的构造函数：

public Point(double x, double y) {
        this.x = x;
        this.y = y; 
}

我如何使用另一个名为 Square 的类并初始化这些点。例如，我想在一个正方形中初始化 4 个点。我怎样才能做到这一点？

我不知道这是否有意义。但是，我尽力了……问我问题，以便我能更好地解释。

4

6 回答 6

5

你的 Square 类应该有一个这样的构造函数：

public Square(Point p1, Point p2, Point p3, Point p4) {
        this.p1 = p1;
        this.p2 = p2;
        this.p3 = p3;
        this.p4 = p4;
}

你像这样初始化你的 Square：

Square s = new Square(new Point(1,1), new Point(2,2), new Point(3,3), new Point(4,4));
于 2012-11-05T14:02:06.727 回答
3

如果您想拥有一个Squarewith for 点，请将它们设为属性：

class Square {
    Point p1, p2, p3, p4;
    public Square() {
      p1 = new Point(0,0);
      p2 = new Point(0,0);
      p3 = new Point(0,0);
      p4 = new Point(0,0);
    }
}

当然，还有无数其他方法来定义和使用它。这将主要取决于您的课程/程序设计您应该选择什么。

于 2012-11-05T14:02:57.607 回答
2

我没有看到问题。您Square只需拥有四个类型的成员，Point这些成员将使用通常的new-syntax 进行初始化：

class Square {
    Point topLeft;

    public Square() {
        topLeft = new Point(0,0);
    }
}
于 2012-11-05T14:01:59.833 回答
2

你可以做

public Shape(Point... points) {
    this.points = points;
}

或者

public Quadrilateral(Point p1, Point p2, Point p3, Point p4) {
    this.p1 = p1;
    this.p2 = p2;
    this.p3 = p3;
    this.p4 = p4;
}

或者

public Square(double x, double y, double size) {
    this.x = x;
    this.y = y;
    this.size = size;
}
于 2012-11-05T14:02:46.620 回答
2

我不确定我是否遵循，但如果你有一个像你说的构造函数，你可以简单地调用new Point(10.0, 15.0)在指定的坐标处创建一个点。

也许你追求的是这样的东西？

class Square {
    private Point upperLeftCorner;
    private Point upperRightCorner;
    private Point lowerLeftCorner;
    private Point lowerRightCorner;

    public Square(double x, double y, double size) {
        upperLeftCorner = new Point(x, y);
        lowerLeftCorner = new Point(x, y+size);
        upperRightCorner = new Point(x+size, y);
        lowerRightCorner = new Point(x+size, y+size);
    }
}
于 2012-11-05T14:05:16.157 回答
0

你是这个意思吗？

java GeoTest [{0.0,0.0}, {0.0,10.0}, {10.0,10.0}, {10.0,0.0}]

代码：

import java.util.Arrays;
public class GeoTest{
    public static void main(String[] args){
        System.out.println(Arrays.toString(new Square(new Point(0,0), new Point(10,10)).getCourners()));
    }
}
class Point{
    private double x;
    private double y;
    public Point(double x, double y) {
            this.x = x;
            this.y = y; 
    }
    public String toString(){
        return new String("{"+x+","+y+"}");
    }
    public double getX(){
        return x;
    }
    public double getY(){
        return y;
    }
}

class Square {
    private Point lowerLeft;
    private Point upperRight;
    /**
     * Assuming x & y axis as follows: 
     * Lower left corner (x,y):0,0 -> upper right corner (x,y): n,n where n > 0
     */
    public Square(Point lowerLeft, Point upperRight){
        this.lowerLeft = lowerLeft;
        this.upperRight = upperRight;
    }
    public Point[] getCourners(){
        return new Point[]{lowerLeft, new Point(lowerLeft.getX(),upperRight.getY()),upperRight, new Point(upperRight.getX(), lowerLeft.getY())};
    }
}
于 2012-11-05T14:19:48.533 回答