简易计算器

import java.util.Scanner;

public class Demo08 {
    //简易计算器
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入第一个数字:");
        int firstNum=scanner.nextInt();
        System.out.println("请输入运算符号:");
        String s=scanner.next();
        System.out.println("请输入第二个数字:");
        int secondNum=scanner.nextInt();

        switch (s){
            case "+":
                System.out.println(add(firstNum,secondNum));
                break;
            case "-":
                System.out.println(del(firstNum,secondNum));
                break;
            case "*":
                System.out.println(mul(firstNum,secondNum));
                break;
            case "/":
                System.out.println(dm(firstNum,secondNum));
                break;
            default:
                System.out.println("输入有误！");
        }
    }
    //加法
    public  static int add(int a,int b){
        return a+b;
    }
    //减法
    public  static int del(int a,int b){
        return a-b;
    }
    //乘法
    public  static int mul(int a,int b){
        return a*b;
    }
    //除法
    public  static int dm(int a,int b){
        return a/b;
    }
}