简单的java面向对象计算器

package Bianliang;
//首先要定义一个类 写一个类方法
public class Jisuanqi {
    double jia1;
    double jia2;

    double jiafa(double a, double b) {
        return a + b;
    }

    double jianfa(double a, double b) {
        return a - b;
    }

    double chengfa(double a, double b) {
        return a * b;
    }

//    double chufa(double a, double b) {
//        if (b==0) {
//            System.out.println("除数不能为零");
//            return 0;
//        } else {
//            return a / b;
//        }
//    }
    int jiafa(int a, int b){
        return a+b;
    }
    int jianfa(int a, int b){
        return a-b;
    }
    int chengfa(int a,int b){
        return a*b;
    }
    void chufa1(int a,int b){
        if(b == 0){
            System.out.println("啊啊啊啊");
            return;
        }else{
            System.out.println("除法的结果:"+a/b);
        }
    }

}

package Bianliang;
//然后实例化这个类 并引用进行使用
public class Main {

    public static void main(String[] args) {        
        Jisuanqi jiafa = new Jisuanqi();
        double a1= jiafa.jiafa(10, 11);
        double a2= jiafa.jianfa(5, 8);
        double a3= jiafa.chengfa(10, 9);
        jiafa.chufa1(3, 0);
        
        System.out.println(a1);
        System.out.println(a2);
        System.out.println(a3);
        System.out.println();
        
    }

}