JAVA用基础语法写一个计算器实现加减乘除

package com.kuang.scanner;

import java.util.Scanner;

public class Demo06 {
    public static void main(String[] args) {
        jisuanqi();
    }
    public static void jisuanqi(){
        Scanner s = new Scanner(System.in);
        while (true){
            System.out.println("请输入第一个数");
            double a = s.nextDouble();
            System.out.println("请输入运算符");
            String type = s.next();
            System.out.println("请输入第二个数");
            double b = s.nextDouble();
            s.close();
            switch (type){
                case "+":
                    System.out.println("结果为："+add(a,b));
                    continue;
                case "-":
                    System.out.println("结果为："+less(a,b));
                    continue;
                case "*":
                    System.out.println("结果为："+Multiply(a,b));
                    continue;
                case "/":
                    System.out.println("结果为："+except(a,b));
                    continue;
                default:
                    System.out.println("无效的运算符");
            }
        }
    }
    //加法方法
    public static double add(double now,double jia){
        return now+jia;
    }
    //减法方法
    public static double less(double now,double jan){
        return now-jan;
    }
    //乘法方法
    public static double Multiply(double now,double cheng){
        return now*cheng;
    }
    //除法方法
    public static double except(double now,double chu){
        return now/chu;
    }
}