Write a program give a string and if first char of every word is capital then it is to be small character and if first char of every word is small then it is to be capital character in c#

using System;

using static System.Console;

namespace CSarpExamples

{

    class UpperLowerchar

    {

        public static string ToUpper(string str)

        {

            string result = str;

            if (!string.IsNullOrEmpty(str))

            {

                var word = str.Split(' ');

                for (int i = 0; i < word.Length; i++)

                {

                    string s = word[i];

                    if (s.Length > 0)

                    {

                        word[i] = s[0].ToString().ToUpper() + s.Substring(1);

                    }

                }

                result = string.Join(" ", word);

            }

            return result;

        }

        public static string ToLower(string str)

        {

            string result = str;

            if (!string.IsNullOrEmpty(str))

            {

                var word = str.Split(' ');

                for (int i = 0; i < word.Length; i++)

                {

                    string s = word[i];

                    if (s.Length > 0)

                    {

                        word[i] = s[0].ToString().ToLower() + s.Substring(1);

                    }

                }

                result = string.Join(" ", word);

            }

            return result;

        }

        static void Main()

        {

            string FinalResult;

            NextLine:

            Console.WriteLine("Enter the string");

            string result = ReadLine();

            FinalResult = result;

            if (FinalResult == result.ToUpper())

            {

                var testResult = ToLower(FinalResult);

                WriteLine(testResult);

                WriteLine();

            }

            else if (FinalResult == result.ToLower())

            {

                var testResult = ToUpper(FinalResult);

                WriteLine(testResult);

                goto NextLine;

            }

            ReadLine();

        }

    }

}

Output: