Question

java中无法将类Point中的构造器Point应用到给定类型

public class Point{ public double distance(){ return Math.sqrt(x*x + y*y); } static void main(String args[]){ Point p = new Point(1,1); System.out.println("p.distance()= " + p.distance()); p = new Point3d(1,1,1); System.out.println("p.distance()= " + p.distance()); } } class Point3d extends Point{ public double distance(){ return Math.sqrt(x*x + y*y + z*z); } }

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Answer 1

public class Point {
	int x,y;
	public Point(int x,int y){
		this.x = x;
		this.y = y;
	}
	public double distance() {
		return Math.sqrt(x * x + y * y);
	}

	public static void main(String args[]) {
		Point p = new Point(1, 1);
		System.out.println("p.distance()= " + p.distance());
		p = new Point3d(1, 1, 1);
		System.out.println("p.distance()= " + p.distance());
	}
}

class Point3d extends Point {
	int z;
	public Point3d(int x, int y,int z) {
		super(x, y);
		this.z = z;
	}

	public double distance() {
		return Math.sqrt(x * x + y * y + z * z);
	}
}