String.IsNullOrWhiteSpace(String) Method

public:
 static bool IsNullOrWhiteSpace(System::String ^ value);

public static bool IsNullOrWhiteSpace(string value);

public static bool IsNullOrWhiteSpace(string? value);

static member IsNullOrWhiteSpace : string -> bool

Public Shared Function IsNullOrWhiteSpace (value As String) As Boolean

Parameters

Returns

true if the value parameter is null or Empty, or if value consists exclusively of white-space characters.

Examples

The following example creates a string array, and then passes each element of the array to the IsNullOrWhiteSpace method.

using System;

public class Example
{
 public static void Main()
 {
 string[] values = { null, String.Empty, "ABCDE", 
 new String(' ', 20), " \t ", 
 new String('\u2000', 10) };
 foreach (string value in values)
 Console.WriteLine(String.IsNullOrWhiteSpace(value));
 }
}
// The example displays the following output:
// True
// True
// False
// True
// True
// True

open System

let values = 
 [| null; String.Empty; "ABCDE"
 String(' ', 20); " \t "
 String('\u2000', 10) |]

for value in values do
 printfn $"{String.IsNullOrWhiteSpace value}"
// The example displays the following output:
// True
// True
// False
// True
// True
// True

Module Example
 Public Sub Main()
 Dim values() As String = { Nothing, String.Empty, "ABCDE", 
 New String(" "c, 20), " " + vbTab + " ", 
 New String(ChrW(&h2000), 10) }
 For Each value As String In values
 Console.WriteLine(String.IsNullOrWhiteSpace(value))
 Next
 End Sub
End Module
' The example displays the following output:
' True
' True
' False
' True
' True
' True

Remarks

IsNullOrWhiteSpace is a convenience method that is similar to the following code, except that it offers superior performance:

return String.IsNullOrEmpty(value) || value.Trim().Length == 0;

String.IsNullOrEmpty value || value.Trim().Length = 0

Return String.IsNullOrEmpty(value) OrElse value.Trim().Length = 0

White-space characters are defined by the Unicode standard. The IsNullOrWhiteSpace method interprets any character that returns a value of true when it is passed to the Char.IsWhiteSpace method as a white-space character.

See also

• IsNullOrEmpty(String)