C# | IsNullOrWhiteSpace() Method Last Updated : 31 Jan, 2019 Comments Improve Suggest changes Like Article Like Report In C#, IsNullOrWhiteSpace() is a string method. It is used to check whether the specified string is null or contains only white-space characters. A string will be null if it has not been assigned a value or has explicitly been assigned a value of null. Syntax: public static bool IsNullOrWhiteSpace(String str) Explanation: This method will take a parameter which is of type System.String and this method will return a boolean value. If the method's parameter list is null or String.Empty, or only contains white-space characters then return True otherwise return False. Example: Input : str = null // initialize by null value String.IsNullOrWhiteSpace(str) Output: True Input : str = " " // initialize by whitespace String.IsNullOrWhiteSpace(str) Output: True Program: To demonstrate the working of the IsNullOrWhiteSpace() Method : csharp // C# program to illustrate // IsNullOrWhiteSpace() Method using System; class Geeks { // Main Method public static void Main(string[] args) { string s1 = null; // for null value always return true bool b1 = String.IsNullOrWhiteSpace(s1); Console.WriteLine(b1); string s2 = " "; // for whitespace value always return true bool b2 = String.IsNullOrWhiteSpace(s2); Console.WriteLine(b2); string s4 = " \n "; // for new line value return true bool b4 = String.IsNullOrWhiteSpace(s4); Console.WriteLine(b4); string s5 = "\t"; // for tab value return true bool b5 = String.IsNullOrWhiteSpace(s5); Console.WriteLine(b5); string s6 = "\r"; // for carriage Return value return true bool b6 = String.IsNullOrWhiteSpace(s6); Console.WriteLine(b6); string s7 = "GFG"; // for s7 it return False bool b7 = String.IsNullOrWhiteSpace(s7); Console.WriteLine(b7); } } Output: True True True True True False Note: There is a alternative code of IsNullOrWhiteSpace() method as follows: return String.IsNullOrEmpty(str) || str.Trim().Length == 0; Program: To demonstrate IsNullOrEmpty() method’s alternative CSharp // C# program to illustrate the // similar code for IsNullOrWhiteSpace() using System; class Geeks { // similar code to // IsNullOrWhiteSpace() public static bool check(string str) { return(String.IsNullOrEmpty(str) || str.Trim().Length == 0) ? true : false; } // Main Method public static void Main(string[] args) { string s1 = "GeeksforGeeks"; string s2 = " "; string s3 = null; string s4 = " \n "; bool b1 = check(s1); bool b2 = check(s2); bool b3 = check(s3); bool b4 = check(s4); // To display result Console.WriteLine(b1); Console.WriteLine(b2); Console.WriteLine(b3); Console.WriteLine(b4); } } Output: False True True True Reference: https://msdn.microsoft.com/en-us/library/system.string.isnullorwhitespace Comment More infoAdvertise with us Next Article C# | IsNullOrWhiteSpace() Method M Mithun Kumar Follow Improve Article Tags : Misc C# CSharp-method CSharp-string Practice Tags : Misc Similar Reads C# | Char.IsWhiteSpace() Method In C#, Char.IsWhiteSpace() is a System.Char struct method which is used to check whether a Unicode character is a whitespace or not. Whitespace characters include Unicode characters of category SpaceSeparator, LineSeparator, ParagraphSeparator etc. This method can be overloaded by passing different 3 min read C# String IsNullOrEmpty() Method In C#, IsNullOrEmpty() is a string method. It is used to check whether the specified string is null or an Empty string. A string will be null if it has not been assigned a value. A string will be empty if it is assigned “†or String.Empty (A constant for empty strings).Example 1: Using IsNullOrEmpty 2 min read C# | Char.IsLower() Method In C#, Char.IsLower() is a System.Char struct method which is used to check whether a Unicode character can be categorized as a lowercase letter or not. Valid lowercase letters will be the members of UnicodeCategory: LowercaseLetter. This method can be overloaded by passing different type and number 3 min read C# | Char.IsUpper() Method In C#, Char.IsUpper() is a System.Char struct method which is used to check whether a Unicode character can be categorized as an uppercase letter or not. Valid uppercase letters will be the members of the UnicodeCategory: UppercaseLetter. This method can be overloaded by passing different type and n 3 min read C# | Char.IsLetter() Method In C#, Char.IsLetter() is a System.Char struct method which is used to check whether a Unicode character can be categorized as a Unicode letter or not. Unicode letters consist of the Uppercase letters, Lowercase letters, Title case letters, Modifiers letters and Other letters. This method can be ove 3 min read C# | Char.IsNumber() Method In C#, Char.IsNumber() is a System.Char struct method which is used to check whether a Unicode character can be categorized as a number or not. Valid numbers will be the members of the UnicodeCategory.DecimalDigitNumber, UnicodeCategory.LetterNumber, or UnicodeCategory.OtherNumber category. This met 3 min read C# | Char.IsLetterOrDigit() Method In C#, Char.IsLetterOrDigit() is a System.Char struct method which is used to check whether a Unicode character can be categorized as a letter or decimal digit. Valid letters and decimal digits will be the members of the UnicodeCategory: UppercaseLetter, LowercaseLetter, TitlecaseLetter, ModifierLet 3 min read Character.isWhitespace() method in Java with examples The java.lang.Character.isWhitespace() is an inbuilt method in a java that determines if the specified character (Unicode code point) is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria: It is a Unicode space characte 3 min read Character.isSpaceChar() method in Java The java.lang.Character.isSpaceChar(char ch) is an inbuilt method in java which determines if the specified character is a Unicode space character. A character is considered to be a space character if and only if it is specified to be a space character by the Unicode Standard. This method returns tr 2 min read C# | Char.IsSeparator ( ) Method In C#, Char.IsSeparator() is a System.Char struct method which is used to check whether a Unicode character can be categorized as a separator character or not. This method can be overloaded by passing different type and number of arguments to it. Char.IsSeparator(Char) MethodChar.IsSeparator(String, 3 min read Like