给出两个方法求圆的面积和周长

Question

其中坐标为（x,y）半径为r，输出计算圆的面积与周长的结果。

Answer 1

public class A {

    public static void main(String[] args) {
        Circle circle = new Circle(6);
        circle.area();
        circle.perimeter();
    }
    
}

class Circle{
    
    private int x = 0;
    private int y = 0;
    private double r = 0;
    private final double PI = 3.14;
    
    public Circle(double r) {
        this.r = r;
    }
    
    public void area() {
        System.out.println("面积："+PI * r * r);
    }
    
    public void perimeter() {
        System.out.println("周长："+2 * PI * r);
    }
}