I was tasked to implement from scratch the getElementsById native method in Javascript. I was also tasked to implement JSON.Stringify from scratch.
I learned a lot about recursion. I was encouraged through this project to really whiteboard and visualize what is going on behind the Javascript interpreter as I recurse over and over through functions. I also learned the importance of choosing let vs var in for loop scopes (especially in the context of recursion).
This is a project I completed as a student at hackreactor. This project was worked on with a pair.