How to branch processing when the value is "null" and when the value is an "empty character"

Question

I would like to branch processing when the value of a script variable is "null" or when it is an "empty character" with "Conditional Branch".

Answer

It is impossible to branch processing when the value of a script variable is "null" or when it is an "empty character" with "Conditional Branch" because a script variable is used as the default value of the specified data type when "null" is assigned to the script variable.
e.g. Strings type - empty character

-Workaround
It is possible to branch processing with "Conditional Branch" by using [Replace Null] or [Convert Null/Empty String] and setting alternative characters to a script variable.

[Replace Null]
https://www.hulft.com/help/en-us/HULFTSquare/Content/Designer/Mapper/ReplaceNull.htm

[Convert Null/Empty String]
https://www.hulft.com/help/en-us/HULFTSquare/Content/Designer/Mapper/ReplaceNullBlankWithString.htm

-Reference
The following manual provides information on the behavior when "null" is assigned to a script variable.
[Script Variables] - [Notes]
https://www.hulft.com/help/en-us/HULFTSquare/Content/Data_Integration/Detailed/script_variables.htm