why use arrow function in javascript code example

Example 1: js anonymous function es6

// (param1, param2, paramN) => expression

// ES5
var multiplyES5 = function(x, y) {
  return x * y;
};

// ES6
const multiplyES6 = (x, y) => { return x * y };

Example 2: 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; };

Example 3: arrow function javascript

//If body has single statement
let myFunction = (arg1, arg2, ...argN) => expression

//for multiple statement
let myFunction = (arg1, arg2, ...argN) => {
    statement(s)
}
//example
let hello = (arg1,arg2) => "Hello " + arg1 + " Welcome To "+ arg2;
console.log(hello("User","Grepper"))
//Start checking js code on chrome inspect option

Example 4: () => javascript

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]

Example 5: arrow function javascript

// Traditional Function
function (a){
  return a + 100;
}

// Arrow Function Break Down

// 1. Remove the word "function" and place arrow between the argument and opening body bracket
(a) => {
  return a + 100;
}

// 2. Remove the body brackets and word "return" -- the return is implied.
(a) => a + 100;

// 3. Remove the argument parentheses
a => a + 100;

Example 6: arrow function javascript

// Traditional Function
function (param) {
  var a = param * 3;
  return a;
}

//Arrow Function
(a, b) => {
  let c = (a * b) + 3;
  return c;
}