String.IsNullOrEmpty() vs. String.IsNullOrWhiteSpace() farkı

IsNullOrEmpty: içeriğin null veya boş olması kontolüdür. Fakat içerisinde boşluk(space) olması durumunda bu kontrol false değeri döner.
IsNullOrWhiteSpace: İçeriğin null veya boşluk(space) olması durumunu kontrol eder.

string testString = "";
Console.WriteLine(string.Format("IsNullOrEmpty : {0}", string.IsNullOrEmpty(testString)));
Console.WriteLine(string.Format("IsNullOrWhiteSpace : {0}", string.IsNullOrWhiteSpace(testString)));
Console.ReadKey();

Resutl :
IsNullOrEmpty : True
IsNullOrWhiteSpace : True

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string testString = " MDS   ";

IsNullOrEmpty : False
IsNullOrWhiteSpace : False

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string testString = "   ";

IsNullOrEmpty : False
IsNullOrWhiteSpace : True

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string testString = string.Empty;

IsNullOrEmpty : True
IsNullOrWhiteSpace : True

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string testString = null;

IsNullOrEmpty : True
IsNullOrWhiteSpace : True