Functions

Can have default parameters, no named parameters when calling though

function scrape(company, secrets, headless=false, toScrape=["All"]) {
    //...
}

Different ways to call ft change how it interacts with the local scope

Using this

Use the this of the scope that defined it: .bind(this) or store the context var self = this or use arrow its

7 Ways to Define Ft

Ft Declaration

function isEven(num) {
  return num % 2 === 0;
}

Creates isEven variable in current scope that hold ft obj, hoists ft up, and names it useful for debugging

Need a name for recursion

Arrow Ft

Takes

const absValue = (number) => {
  if (number < 0) {
    return -number;
  }
  return number;
}

Ft Expression

const isTruthy = function(value) {
  return !!value;
};

allows conditional setting of variable

Name informed for debugging using variable that holds it

Named Ft Expression

const getType = function funName(variable) {
  console.log(typeof funName === 'function'); // => true
  return typeof variable;
}

Name only available in body, and name set as such

Shorthand method definition

Possible on object literals and classes, required in classes

const collection = {
  items: [],
  add(...items) {
    this.items.push(...items);
  },
  get(index) {
    return this.items[index];
  }
};

Generator Ft

function* indexGenerator(){
  var index = 0;
  while(true) {
    yield index++;
  }
}
const g = indexGenerator();
console.log(g.next().value); // => 0
console.log(g.next().value); // => 1

Can also be used with ft expression, and method

const indexGenerator = function* () {
//...
const obj = {
  *indexGenerator() {
//...

Ft New

This is disgusting don't use, always declared in global scope

const global = new Function('return this')();