Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
I like this approach in part because it filters out strings rather than returning numbers.
This code can be used on arrays that contain more data types than just Strings and Numbers,
and will return the array less the Strings.