this code will timeout if num is like 100000

yes... exactly

JS Version:
What if the text is made of numbers？
Like this:
"212"
Some solutions use object({}) and may lead to wrong result.
I think this should be test!

Thanks, it's fixed.

C# Kata has string misspelled.

It's OOP in Python. How is this an issue?

How is this an OOP topic?