Reddit project 2e

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Second___Easy
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Write function (+ - * / % ^): ");
            string operation = Console.ReadLine();
            Console.Write("Write FIRST value (use prefix \"h\" for hexadecimal or \"b\" for binary number): ");
            string firstValue = Console.ReadLine();
            Console.WriteLine("Write SECOND value (use prefix \"h\" for hexadecimal or \"b\" for binary number): ");
            string secondValue = Console.ReadLine();

            int firstNumber = ParseNumber(firstValue);
            int secondNumber = ParseNumber(secondValue);

            int result;
            switch (operation)
            {
                case "+":
                    result = firstNumber + secondNumber;
                    break;
                case "-":
                    result = firstNumber - secondNumber;
                    break;
                case "*":
                    result = firstNumber * secondNumber;
                    break;
                case "/":
                    result = firstNumber / secondNumber;
                    break;
                default:
                    Console.WriteLine("Unknown operation");
                    return;
            }

            Console.WriteLine();
            Console.WriteLine();

            string[] firstOutput = GetAllFormats(firstNumber);
            string[] secondOutput = GetAllFormats(secondNumber);
            string[] resultOutput = GetAllFormats(result);

            Console.WriteLine("In decimal");
            Console.WriteLine("{0} {1} {2} = {3}", firstOutput[0], operation, secondOutput[0], resultOutput[0]);
            Console.WriteLine();
            Console.WriteLine("In binary");
            Console.WriteLine("{0} {1} {2} = {3}", firstOutput[1], operation, secondOutput[1], resultOutput[1]);
            Console.WriteLine();
            Console.WriteLine("In hexadecimal");
            Console.WriteLine("{0} {1} {2} = {3}", firstOutput[2], operation, secondOutput[2], resultOutput[2]);
            Console.WriteLine();

            Console.ReadKey();
        }

        private static string[] GetAllFormats(int result)
        {
            string[] retVal = new string[3];
            retVal[0] = result.ToString();
            retVal[1] = Convert.ToString(result, 2);
            retVal[2] = Convert.ToString(result, 16);
            return retVal;
        }

        private static int ParseNumber(string value)
        {
            if (value[0] == 'b' || value[0] == 'B')
            {
                value = value.Substring(1);
                return Convert.ToInt32(value, 2);
            }

            if (value[0] == 'h' || value[0] == 'H')
            {
                value = value.Substring(1);
                return Convert.ToInt32(value, 16);
            }

            return int.Parse(value);
        }
    }
}