using System;

​

namespace StringIsNullOrWhiteSpace

{

    public class Program

    {

        public static void Main(string[] args)

        {

            string value1 = "Merhaba Dünya";

            string value2 = "";

            string value3 = " ";

            string value4 = null;

​

            Console.WriteLine(string.IsNullOrWhiteSpace(value1));

            Console.WriteLine(string.IsNullOrWhiteSpace(value2)); 

            Console.WriteLine(string.IsNullOrWhiteSpace(value3));

            Console.WriteLine(string.IsNullOrWhiteSpace(value4));

​

            Console.ReadLine();

        }

    }

}