java代码 简易计算器

可实现循环加减乘除：

import java.util.Scanner;

public class test50 {
    public static void main(String[] args) {
        while(1 == 1)
            counter();
    }
    public static double add(double a, double b){
        return a + b;
    }
    public static double sub(double a, double b){
        return a - b;
    }
    public static double mul(double a, double b){
        return a * b;
    }
    public static double div(double a, double b){
        return a / b;
    }
    public static void counter(){
        double out = 0;
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入第一个数字");
        double i = sc.nextDouble();
        System.out.println("请输入要做的运算");
        char m = sc.next().charAt(0);
        System.out.println("请输入第二个数字");
        double j = sc.nextDouble();
        switch(m){
            case '+' : out = add(i, j); break;
            case '-' : out = sub(i, j); break;
            case '*' : out = mul(i, j); break;
            case '/' : out = div(i, j); break;
        }
        System.out.println("out = " + out);
        System.out.println("-------分割线-------");
    }
}