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.
This one is a little easier to debug than the top answer. This is better for a team environment.
I love how you use the primitive char, but yes you need to if check for size 4 or less and return the string
It's not thread safe
That's Java 11 or later