javascript arrow function

// Non Arrow (standard way)
let add = function(x,y) {
  return x + y;
}
console.log(add(10,20)); // 30

// Arrow style
let add = (x,y) => x + y;
console.log(add(10,20)); // 30;

// You can still encapsulate
let add = (x, y) => { return x + y; };hello = () => {
  return "Hello World!";
} /*this is an arrow function 
you can call it like an reqular function
and allow you to write shorter function syntaxes*/

hello = () => {
  return "Hello World!";
}

//for function that returns one static value you can do this

hello = () => "Hello World!";var a = [
  "We're up all night 'til the sun",
  "We're up all night to get some",
  "We're up all night for good fun",
  "We're up all night to get lucky"
];

// Sans la syntaxe des fonctions fléchées 
var a2 = a.map(function (s) { return s.length });
// [31, 30, 31, 31]

// Avec, on a quelque chose de plus concis
var a3 = a.map( s => s.length);
// [31, 30, 31, 31]multiplyfunc = (a, b) => { return a * b; }function add(a, b) {
  return a + b;
}

var add = (a, b) => {
  return a + b;
}

var add = (a, b) => a + b;