• false
• undefined
• null
• 0
• NaN
• the empty string ''

• instanceof  (works for objects, but not primitives)
• typeof (works for primitives)      

• The first letter of a variable can only be "$", "_", "a" to "z", or "A" to "Z".
• Use "camel" convention (e.g. carName)
• For constants use caps (e.g. HEIGHT)

• 'Local' (within function), and 'Global' (anywhere in program) [E6 added 'block' scope]
• 'let' can be used to limit scope to block of code in a function
  
• Javascript doesn't require declaration, but best practice is to declare variables as intended
• Scope examples can be found here

shortform:
groceries.forEach(groceryItem => console.log(' - ' + groceryItem));

Note: returns undefined; original array won't change

let numbers = [1, 2, 3, 4, 5]; 
let bigNumbers = numbers.map(function(number) {
 return number * 10;});

shortform:
let numbers = [1, 2, 3, 4, 5]; 
let bigNumbers = numbers.map(numbers => numbers * 10);

Note: returns new array

let shortWords = words.filter(function(word) {
 return word.length < 6;
});

let shortWords = words.filter(word => word.length < 6);

A list of iterator methods can be found here. 

               
                              function f() {...}  //basic form
                              e.g.  
                              function f(s) { 
                              return s*2; 
                            } 


                            const square = function (number) { //function expression syntax 
                            return number * number; 
                          }; 
                          var today = function today() {return new Date()}  // Named function expression (NFE)


                          const f = () => { ... }  // arrow function syntax 
                          e.g.
                          const getSubTotal = (itemCount, PRICE) => { 
                          return (itemCount*PRICE) 
                        } 

                        const f = .. => ..  // concise arrow function syntax (one paramater only)
                        const f = () =>     // arrow function syntax with implied return
                        e.g.
                        const f = x => x*7
                        const h = (x,y) =>  x*y
                      } 


                      Functions can also take default arguments 

                      There are important differences between function expressions and declarations (e.g. expressions don't get hoisted; functions can't be defined within non-function blocks)
                    

• instanceof  (works for objects, but not primitives)
• typeof (works for primitives)      
• {}.toString

class Dog {
  constructor(name) {
    this.name = name;
    this.behavior = 0;
  }
}

const halley = new Dog('Halley')

get behavior() {
    return this._behavior;
  }



console.log(bryceCat.behavior);
nurseOlynyk.addCertification('Genetics');

incrementBehavior() {
    this._behavior++;
  }

 takeVacationDays (daysOff){
    this._remainingVacationDays -= daysOff
  }

bryceCat.incrementBehavior()

Class Nurse extends HospitalEmployee {
  constructor (name,certifications) {
    super(name);
    this._certifications = certifications;
  }

}

const nurseOlynyk = new Nurse ('Olynyk', ['Trauma', 'Pediatrics'])

console.log(`JavaScript first appeared ${a+b} years ago. Crazy!`);

let Menu = {};
Menu.specialty = "Roasted Beet Burger with Mint Sauce";
module.exports = Menu;


let Menu = {};
module.exports = {
  specialty: "Roasted Beet Burger with Mint Sauce",
  getSpecialty: function() {
    return this.specialty;
  } 
};

let Menu = {};
export default Menu;


let Airplane = {}
Airplane.availableAirplanes = [
  {
    name: 'AeroJet', 
    fuelCapacity: 800 
  },
  {
    name: "SkyJet", 
    fuelCapacity: 500
  }
];
export default Airplane;

const Menu = require('./menu.js');
console.log(Menu.getSpecialty());

import Menu from './menu';


import Airplane from './airplane';
function displayFuelCapacity() {
  Airplane.availableAirplanes.forEach(function(element){
    console.log(
`Fuel Capacity of ${element['name']} : ${element.fuelCapacity}`
    )  
  })
}
displayFuelCapacity()

in Bash:
npm install babel-cli
npm install babel-preset-env
npm run build
npm init

npm install babel-cli -D
npm install babel-preset-env -D

summary