Switch和scanner写一个计算器

package com.xl.method;

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        //创建对象调用函数
        Calculator calculator = new Calculator();
        //创建Scanner扫描对象,获取用户输入数据
        Scanner scanner = new Scanner(System.in);

        //请输入第一个数据
        System.out.println("请输入一个数据： ");
        double a =scanner.nextDouble();
        //请输入运算符
        System.out.println("请输入运算符：");
        String operator = scanner.next();
        //请输入第二个数据
        System.out.println("请输入第二个数据");
        double b = scanner.nextDouble();

        //存储最终计算结果
        double result = 0;
        //关闭scanner资源
        scanner.close();
        //根据输入运算符调用不同的方法
        switch (operator){
            case "+"://调用加法
                result = calculator.add(a,b);
                System.out.println("结果为"+result);
                break;
            case "-"://调用减法1
                result = calculator.sub(a,b);
                System.out.println("结果为"+result);
                break;
            case "*":
                result = calculator.multiply(a,b);
                System.out.println("结果为"+result);
                break;
            case "/":
                result = calculator.div(a,b);
                System.out.println("结果为"+result);
                break;
        }

    }

    //加法
    public double add (double a,double b){
        return a + b;
    }
    //减法
    public double sub (double a,double b){
        return a - b;
    }
    //乘法
    public double multiply (double a,double b){
        return a * b;
    }
    //除法
    public double div (double a,double b){
        return a / b;
    }




}