String.prototype.split() - JavaScript | MDN (mozilla.org)
Some friendly advice:
Don’t rely solely on FCC challenges for learning. Also learn to look up reference materials etc… (I also believe this would be an important skill once I’m actually working as a developer).
FCC expects that you’d have questions beyond the scope of what’s taught in their challenges, and that’s why they suggest the Read-Search-Ask method for solving challenges.
I’m currently working on the final projects for the third certification and I’ve been feeling strongly that FCC’s non-project challenges are intended to be introductory. To be able to complete the final projects, you do need to do some additional research and reading.