Return value from Main

Create a new version of the program Main parameter calculator where you can return the following error codes from Main:

• Return 1 if the total parameters are different from 3.
• Return 2 if the second parameter is not a valid arithmetic sign (+, -, x, *, /).
• Return 3 if the first or third parameter is not a valid number.
• Return 0 if everything is correct.

Input

2 x 2

Output

4

Solution

using System;
public class MainParametersCalculator
{
    public static int Main(string[] args)
    {
        if (args.Length != 3)
        {
            return 1;
        }

        int num1 = 1, num2 = 1;
        try
        {
            num1 = Convert.ToInt32(args[0]);
            num2 = Convert.ToInt32(args[2]);
        }
        catch
        {
            return 3;
        }

        char operation;
        if (args[1] == "+" || args[1] == "-" || args[1] == "*" || args[1] == "/")
        {
            operation = Convert.ToChar(args[1]);
        }
        else
        {
            return 2;
        }

        switch (operation)
        {
            case '+':
                Console.WriteLine(num1 + num2);
                break;
            case '-':
                Console.WriteLine(num1 - num2);
                break;
            case '*':
                Console.WriteLine(num1 * num2);
                break;
            case '/':
                Console.WriteLine(num1 / num2);
                break;
        }

        return 0;
    }
}