Common Array coding interview question solved with a Regular Expression in Javascript

Both Amazon and Slack have had me work through some variation of this coding challenge.
There's a main array, derived from a company database. The user is looking for a particular value in that array. The user types keystrokes in a search box within a webpage. Once the user types 3 keystrokes, they should get an object such as a drop down list, that gives them options, or values from the main array, based on their input.

The solution I have delivered here is based on Regular Expressions (RegEx).

By the way, I couldn't think of the term at the time of shooting, but the "i" in the RegEx expression stands for case Insensitive. Not case indifferent. Sorry for the confusion. Also, the other event is actually called keydown, not keystroke.