using System; public class Class1 { public static void Main(string[] strings) { Example exampleObject = new Example(); Console.WriteLine("Pass a null object:"); string s = null; exampleObject.TestString(s); Console.WriteLine(); Console.WriteLine("Pass an empty string:"); exampleObject.TestString(""); Console.WriteLine(); Console.WriteLine("Pass a real string:"); exampleObject.TestString("test string"); Console.WriteLine(); } } class Example { public void TestString(string sTest) { if (sTest == null) { Console.WriteLine("sTest is null"); return; } if (String.Compare(sTest, "") == 0) { Console.WriteLine("sTest references an empty string"); return; } Console.WriteLine("sTest refers to: '" + sTest + "'"); } }