> For the complete documentation index, see [llms.txt](https://documentation.astera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.astera.com/astera-data-stack-v9/functions/logical/isnullorwhitespace-stringvalue.md).
# IsNullOrWhitespace (StringValue)
| **Name** | ***IsNullOrWhitespace (String)*** |
| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Syntax | IsNullOrWhitespace (String val) |
| Purpose | To determine whether a string is null, if its length is zero, or if it contains only white space characters. |
| Description |
Returns true if the specified string contains null value, if string length is zero, or if a string contains only white space characters.
Note: White space characters are space, tab, return, and linefeed.
|
| Return Type | Boolean |
| Parameters | val \[System.String] – Expression that will be evaluated |
**Example**
In this example, we will pass a whitespace value to the function transformation object using a *Variables* object.
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In the output, you can see that the Boolean value, True, has been returned as the passed value consisted of whitespaces. If the same variable was passed through the *IsNullOrEmpty* function, The output would be false.
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