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.
Use
[].map.callon the given stringstrto map over its characters while avoiding the creation of a possibly big intermediate array of characters.I'm having trouble seeing how this works...could you explain?