An empty string has a length of zero.
To create an empty string, you can use either a literal or the static string.Empty field.
To test for an empty string, you can either perform an equality comparison or test its Length property:
using System; class MainClass{/*from ww w. ja v a 2s. c o m*/ public static void Main(string[] args){ string empty = ""; Console.WriteLine (empty == ""); // True Console.WriteLine (empty == string.Empty); // True Console.WriteLine (empty.Length == 0); // True } }
Because strings are reference types, they can also be null:
using System; class MainClass{/*from ww w.java 2s.c o m*/ public static void Main(string[] args){ string nullString = null; Console.WriteLine (nullString == null); // True Console.WriteLine (nullString == ""); // False Console.WriteLine (nullString.Length == 0); // NullReferenceException } }
static string.IsNullOrEmpty method tells whether a given string is either null or empty.