JavaScript is general purpose, high level, interpreted, dynamically typed programming language.
Versatile, widely used, open source … the language of the web
You can use it primary to write Browser and/or Web server application.
Scope in every programming language including JavaScript designates the accessibility/visibility and lifetime of variables and Functions.
Callback is function passed as argument or stored in variable which is called at later time.
closure is a function that returns a function which continues to have access to the local environment as long as it is active.
A group statements that can be treated as single unit. In general blocks are surrounded by curly brackets.
When a variable in the current inner scope has the same name as variable in outer scope. In this case as you may suspect the inner-scope-variable takes precedence.
== is used to compare two variables, === compares two variables and their types
Prototype is the mechanism by which any object/class inherits features from other objects/classes.
constructor is a method that is executed upon object creation.
Object is instance of class description.
Data structure that allows to store list of items. Specifically JS arrays allow you to store items of different types.
Properties are Object variables aka Attributes.
There are 7 primitive data types: string, number, bigint, boolean, null, undefined, and symbol.
NULL in JavaScript was designed with a view to enable interoperability with Java.
Represent absence of value.
