package Sum; import java.util.*; class Rect { double length; double width; double perimeter; double area; //长宽面积周长成员变量 Rect(double n, double k) { length = n; width = k; } //构造方法 将值赋给成员变量 double area1() { area = length * width; return area; } //计算返回面积 double perimeter1() { perimeter = 2 * (length + width); return perimeter; } //计算返回周长 } public class Rectangle { public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("请输入矩形的长和宽:"); Scanner reader = new Scanner(System.in); double num1 = reader.nextDouble(); double num2 = reader.nextDouble(); Rect a = new Rect(num1, num2); //创建对象 System.out.println("矩形的面积为:" + a.area1()); System.out.println("矩形的周长为:" + a.perimeter1()); } }