using System;

​

namespace FindWordInString

{

    class Program

    {

        static void Main(string[] args)

        {

            string sentence = "Hello, my name is Janvi.";

            string word = "Hello";

​

            int startIndex = sentence.IndexOf(word);

​

            if (startIndex >= 0)

            {

                // Check if the word is surrounded by spaces or punctuation

                bool isWholeWord = (startIndex == 0 || !char.IsLetter(sentence[startIndex - 1])) &&

                                   (startIndex + word.Length == sentence.Length || !char.IsLetter(sentence[startIndex + word.Length]));

​

                if (isWholeWord)

                {

                    Console.WriteLine("The word '{0}' was found in the sentence.", word);

                }

                else

                {

                    Console.WriteLine("The word '{0}' was not found as a whole word in the sentence.", word);

                }

            }

            else

            {

                Console.WriteLine("The word '{0}' was not found in the sentence.", word);

            }

​

            Console.ReadLine();

        }

    }

}

​