What is scope? Your explanation should include the idea of global vs. local scope.
Scope is the context in which the variable exists. Global scope has variables declared outside of a function;
local scope includes variables declared within a function and which are only accessible within that function.

Why are global variables avoided?
Global variables should be avoided because they are available to the entire document, and could cause
confusion down the line with larger files with lots of lines of code.

Explain JavaScript's strict mode
In strict mode, "use strict"; is added to the top of your code, before anything else. It enforces better
programming practices and can prevent errors from occurring or flags errors immediately.

What are side effects, and what is a pure function?
A pure function is a specific kind of function that always behaves the same and produces the same
value every time. Functions with side effects can return something other than a value.

Explain variable hoisting in JavaScript.
Hosting moves declarations to the top by default.