When you dynamically invoke a user-defined function, get an attribute, or run a method, RETURN-VALUE-DATA-TYPE lets you do one of the following to the return value:
Detect its data type
Cause it to be converted to a different data type
If you set RETURN-VALUE-DATA-TYPE to a data type other than the expected data type before executing the dynamic invoke, the value returned is automatically converted to that data type. Otherwise, when the dynamic invoke returns, RETURN-VALUE-DATA-TYPE indicates the data type of the value returned.
Detect its data type