• String.Contains Method

using System;
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string text = "I will be there";
            if (text.Contains("will"))
            {
                Console.WriteLine("Yes");
            }
            else
            {
                Console.WriteLine("No");
            }
            // Yes
            if (text.Contains("not"))
            {
                Console.WriteLine("Yes");
            }
            else
            {
                Console.WriteLine("No");
            }
            // No
        }
    }
}