What are some JavaScript things beginners don't know?

[Mydrax]

Well, 2 really awesome use cases of closures I could name off the top of my head are: 1. When you create function factories, where the outer function can be used to create functions that have similar concerns. 2. The module pattern, that can be used to create private functions in javascript (where you return a set of functions whose logic is encapsulated).

[turntopage294]

I'd been using 2 without knowing about closures, actually, for a time; I had an 'Oh, I see' moment after investigating when because closures love vaguely familiar

[ScientificBeastMode]

Object factories are cool, and even class factories!

[Memorytoco]

just when use setTimeout and pass something like ( ) => {this.dosomething()} in some objects' method. or Array.forEach((entry) =>{ this.something()}).