Java——封装意义类定义和使用方法

「爱情、让人受尽委屈。」 2022-12-19 13:26 116阅读 0赞

## 定义一个描述二维点的类（如Point2D），提供不带参数和带参数的构造方法； ##

> 提供distance（int x, int y）和distance(Point2D p)方法用于计算两点之间的距离。  
> 使用该类描述任意多边形，使用类的distantce方法计算此多边形的周长

private int x;// x坐标
    	private int y;// y坐标
    
    	// 不带参数的构造方法
    	public Point() { 
    	}
    
    	// 带两个参数的构造方法
    	public Point(int x, int y) { 
    		this.x = x;
    		this.y = y;
    	}
    
    	public int getX() { 
    		return x;
    	}
    
    	public void setX(int x) { 
    		this.x = x;
    	}
    
    	public int getY() { 
    		return y;
    	}
    
    	public void setY(int y) { 
    		this.y = y;
    	}
    
    	// 求两点的距离
    	public int distance(Point b) { 
    		return (int) Math.sqrt((this.x - b.getX()) * (this.x - b.getX()) + (this.y - b.getY()) * (this.y - b.getY()));
    	}
    
    	public static void test() { 
    		Point A = new Point();
    		Point B = new Point(50, 60);
    		A.setX(80);
    		A.setY(100);
    		System.out.println("A: (" + A.getX() + "," + A.getY() + ") ");
    		System.out.println("B: (" + B.getX() + "," + B.getY() + ") ");
    		System.out.println("A->B 的距离为：" + A.distance(B));
    	}
    
    	public static void test2() { 
    		System.out.println("------------------------------------------");
    		Point a = new Point(-10, 10);
    		Point b = new Point(10, 10);
    		Point c = new Point(10, -10);
    		Point d = new Point(-10, -10);
    		System.out.println("a: (" + a.getX() + "," + a.getY() + ") ");
    		System.out.println("b: (" + b.getX() + "," + b.getY() + ") ");
    		System.out.println("c: (" + c.getX() + "," + c.getY() + ") ");
    		System.out.println("d: (" + d.getX() + "," + d.getY() + ") ");
    		System.out.println("C为：" + (a.distance(b)+b.distance(c)+c.distance(d)+d.distance(a)));
    	}
    
    	public static void main(String[] args) { // 测试的main方法
    		test();
    		test2();
    		
    	}

![点距][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0dvZE91Tw_size_16_color_FFFFFF_t_70_pic_center]

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