CSharp-Learning/lessons/Lesson05/Helpers/MathHelper.cs

using System;

namespace Lesson05.Helpers
{
    static class MathHelper
    {
        public static int Add(int a, int b)
        {
            return a + b;
        }

        public static int Multiply(int a, int b)
        {
            return a * b;
        }

        public static double Divide(int a, int b)
        {
            if (b == 0)
            {
                Console.WriteLine("除数不能为0！");
                return 0;
            }
            return (double)a / b;
        }
    }
}