Obie 0bie

Provide a way to draw a distinction between the characteristics of properties, such as whether the property was read-only or not.

var myObject = {
  a: 2
};

Object.getOwnPropertyDescriptor(myObject, 'a'); // => {value: 2, writable: true, enumerable: true, configurable: true}

Call-site: The location in code where a function is called (not where it's declared). Usually the call-site we care about is in the invocation before the currently executing function
Call-stack: The stack of functions that have been called to get us to the current moment in execution
Closure:
- When a function still has reference to its outer scope (parameters, variables, functions) even after that outer function has been executed.
- Closure is when a function is able to remember and access its lexical scope even when that function is executing outside its lexical scope E.g

The ability to store values and pull values out of variables is what gives a program state.
A well defined set of rules for storing variables in some location, and for hiding those variables at a later time: SCOPE
Abstract Syntax Tree (AST): The grammatical structure of a program
Any snippet of JS has to be compiled before (usually right before) it's executed

When a function is invoked on or through an object, that object is the invocation context or this value for the function.
Functions designed to initialize a newly created object are called constructors

Update npm: npm install npm --global || npm i npm -g
New package: npm init --yes || npm init -y
Scopes: npm init --scope=myusername npm install @myusername/mypackage require('@myusername/mypackage')
Add dependencies: npm install --save package-name || npm i -s package-name
Add devDependencies: npm install --save-dev package-name || npm i -D package-name
Skip devDependencies: npm install --production
Add bundled dependencies: npm install --save --save-bundle package-name
Update dependencies: npm outdated && npm update

An ES2016 decorator is an expression which returns a function and can take a target, name and property descriptor as arguments.
A decorator takes an argument (the function being decorated) and returns the same function with added functionality.
Decorators are helpful for anything you want to transparently wrap with extra functionality.

const HOC = (Component) => (props) => <Component {...props} />;

	// callback examples
	function loadImage(src, parent, callback) {
	const img = document.createElement('img');
	img.src = src;
	img.onload = callback;
	parent.appendChild(img);
	}

	const imgContainer = document.body;

	const overlay = (element) => {
	const newElement = document.createElement(element);
	newElement.style.height = '100vh';
	return newElement;
	};

	const onEvent = (inputType, DOMElement, callback) => {
	if (DOMElement.addEventListener){
	DOMElement.addEventListener(inputType, callback);
	}

Intro: