The FILE_EXTENSION function takes a single parameter, normally an external data property, and returns the file extension referenced by that property as a string. This function is intended for use with external data properties as a part of the attached document’s functionality. If the external data property provided as a parameter does not currently reference a file, the function will return an empty string. The return value from this function is undefined when the parameter provided is not an external data property.
| @FILE_EXTENSION (File Name) | |
|---|---|
File Name | Required string parameter; specifies the file whose file extension
is to be returned. While the data type of this parameter is a string,
the intended parameter is a property of data type external data.
The file extension of the file referenced by such a property is
returned by this function. If the property does not reference a
file, the function returns an empty string. |
String