when were arrow functions introduced in javascript code example

Example 1: 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 2: arrow function in javascript

//function old way
function PrintName(name){
  console.log("my name is ", name) ;
}
// Arrow function es6
const PrintName =  (name) => {
  return console.log("my name is " , name) ;
}

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: arrow function javascript

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

// Arrow Function
let bob = a => a + 100;

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: es6 arrow function

// ES6
const prices = smartPhones.map(smartPhone => smartPhone.price);
console.log(prices); // [649, 576, 489]