Java练习 利用循环和Switch写一个计算机

package com.zhang.method;

import java.util.Scanner;

public class jisuanqi {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入第一个数");
        double a = scanner.nextDouble();
        System.out.println("请输入第二个数");
        double b = scanner.nextDouble();
        System.out.println("请输入计算方法+ - * /");
        String c =scanner.next();

        switch (c){
            case "+":
                System.out.println(jia(a,b));
                break;
            case "-":
                System.out.println(jian(a,b));
                break;
            case"*":
                System.out.println(cheng(a,b));
                break;
            case"/":
                System.out.println(chu(a,b));
                break;

        }



    }
    public static double jia(double a,double b){
        return a+b;
    }
    public static double jian(double a,double b){
        return a-b;
    }
    public static double cheng(double a,double b){
        return a*b;
    }
    public static double chu(double a,double b){
        if (b==0){
            System.out.println("被除数不能为0");
            return 0;
        }else{
            return a/b;
        }
    }
}