Programming - JS by Jamie

We use a package called dotenv to protect variables like username, passwords and api keys on the backend in express, and also on the frontend with React to save things that might be repeated like the website URL in api calls.

A logger middleware for node/express will save data about every api request and log it so that developers can see exactly what happened with the request.

A function that returns the result of another function is using function composition.

Promises help JS appear to run code asynchronously. JS runs synchronously on one thread. A promise runs the code, but says continue running other code and I will let you know when this code returns data. fetch() is just a promise that gets an api. async/await is syntactic sugar for running promises.

Javascript was not built to be used as an Object Oriented Programming language. So at first, using OOP in JS was weird and awkward. But it has come a long way and its evolution is explained in detail here.

Top 20 questions most JS developers get stumped on. They are pretty basic and if you are a JS developer you should know most of them off the top of your head. But you may need a refresher on a few.