C# | IsNullOrWhiteSpace() Method

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 : 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

Reference: https://learn.microsoft.com/en-us/dotnet/api/system.string.isnullorwhitespace?redirectedfrom=MSDN#System_String_IsNullOrWhiteSpace_System_String_