//pure functions
//given a input will always return a same output
//will not cause side effects
const add = (a, b) => a + b;

//impure function 1
const magicLetter = "*";
const createMagicPhrase = (phrase) => `${magicLetter}abra${phrase}`;

//impure function 2
const fetchLoginToken = externalAPI.getUserToken;

//Closure
//Ex:

//Hoisting
//Ex:
console.log(x); // undefined
var x = 2;
console.log(x); //2

//let and const are hoisted but not assigned a value so will throw error
//Ex:
var x = 10;
{
  console.log(x); //throws undefined error
  let x = 20;
}

//IIFE
// Why IIFE
var x = 10;
console.log(x);
(function () {
  console.log(x);
  var x = 2;
  console.log(x);
})();

// .call .apply .bind
// ES6 Features
// Node Architecture

if (new Boolean(false)) {
  console.log("TEST");
}

//function hoisting
foo();
var foo = function () {
  console.log("TEST");
};

//Promises

let data = {
  name: "viknesh",
};

let data_1 = data;
data_1.name = "xyz";

console.log(data);

//first class functions

// node advantage vs disadvantage