java 子类继承父类（构造方法）

public class hello {

	public static void main(String[] args) {
		Point3d p3d = new Point3d(1,2,3);
		System.out.println(p3d.x + p3d.y + p3d.z);
	}
}
class Point{
	int x,y;
	Point(int x,int y){
		this.x=x;
		this.y=y;
	}
}
class Point3d extends Point{//x,y,z
	int z;
	Point3d(int x, int y,int z){
		super(x,y);
		this.z=z;
	}
}

结果为6

子类继承父类的构造参数并在继承的构造方法中构造这些参数