String.IsNullOrWhiteSpace Method
Indicates whether a specified string is null, empty, or consists only of white-space characters.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System.String
The string to test.
Return Value
Type: System.Booleantrue if the value parameter is null or String.Empty, or if value consists exclusively of white-space characters.
IsNullOrWhiteSpace is a convenience method that is equivalent to the following code, except that it offers superior performance:
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.
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 Demo(System.Windows.Controls.TextBlock outputBlock) { string[] values = { null, String.Empty, "ABCDE", new String(' ', 20), " \t ", new String('\u2000', 10) }; foreach (string value in values) outputBlock.Text += String.IsNullOrWhiteSpace(value) + "\n"; } } // The example displays the following output: // True // True // False // True // True // True
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