Don't Maintain a Sorted Array
Most likely, you should use a dictionary.
How to Solve a Difficult Problem
Good problems teach you how to think.
Wrong Way to Make a 2D Array in JavaScript
Yet another pitfall in the land of JavaScript.
Hand Drawing 2D Arrays
Let me share my little findings.
Sidecar Pattern
Sidecar pattern is a useful coding strategy for a coding challenge.
"for ... of" and "for ... in"
Know that they are different beasts.
How to make an object with alphabet keys in JavaScript?
Do you have a better idea? I pulled it out in an elegant way.