构造 四则运算

public class Calculator {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stub    Yunsuan yunsuan = new Yunsuan(3,5);    System.out.println(yunsuan.add());    System.out.println(yunsuan.reduce());    System.out.println(yunsuan.multiply());    System.out.println(yunsuan.divide());}}class Yunsuan{double a,b;double add(){return a+b;}double reduce(){return a-b;}double multiply(){return a*b;}double divide(){return a/b;}Yunsuan(){}Yunsuan(double a,double b){this.a=a;this.b=b;}}