singhkumarhemant

// ==> ES6 <== // 
function MyFunc(greeting) { 
  this.greeting = greeting; 
} 

MyFunc.prototype.myTeamArr = function (teamArr) { 
  return teamArr.forEach((player) => { 
    console.log(this.greeting + player); 
  }); 
}; 

singhkumarhemant

function MyFunc(greeting) { 
  this.greeting = greeting; 
} 

MyFunc.prototype.myTeamArr = function (teamArr) { 
  return teamArr.forEach(function (player) { 
    console.log(this.greeting + player); }.bind(this)); // see this 
}; 

var welcomeTeam = new MyFunc('Welcome '); 

singhkumarhemant

var greeting = "Hello"; 
function MyFunc(greeting) { 
  this.greeting = greeting; 
} 

MyFunc.prototype.myTeamArr = function (teamArr) { 
  return teamArr.forEach(function (player) { 
    console.log(this.greeting + player); },this); 
}; 

singhkumarhemant

var greeting = "Hello"; 
function MyFunc(greeting) { 
this.greeting = greeting; 
} 

MyFunc.prototype.myTeamArr = function (teamArr) { 
var that = this; // -->(1) 
return teamArr.forEach(function (player) {
console.log(that.greeting + player); 
}); 

singhkumarhemant

// ==> ES5 <== //

var greeting = "Hello"; 
function MyFunc(greeting) {
  this.greeting = greeting; 
  } 
  
MyFunc.prototype.myTeamArr = function (teamArr) { // -->(3) 
return teamArr.forEach(function (player) { // -->(2) 
// Doesn't work: give undefined 

singhkumarhemant

function myComponent() {
  const button = document.getElementById('myButton'); 
  button.addEventListener('click', () => {
    console.log('I AM CLICK'); 
    this.handleClick(); // lexical `this` 
  }); 
}

singhkumarhemant

const arr = [1, 2, 3];
const squares = arr.map(x => x * x); 

// Traditional function expression
const squares = arr.map(function (x) { return x * x });

singhkumarhemant

//ES5 
var updateNameAndDept_1 = function setNameDept(name, dept) {
return { name: name, dept:dept }; 
}; 

// ES6 
var updateNameAndDept_2 = (name, dept) => ({ name: name, dept:dept });

singhkumarhemant

//ES5
var getDoc_1 = function getDoc() {
  console.log(document); 
}; 

//ES6 
var getDoc_2 = () => { console.log(document); };

singhkumarhemant

//ES5 
function multiply_1(params) { 
  return params * 2 
}
multiply_1(2); // 4 

//ES6
var multiply_2 = params => params * 2 
multiply_2(2); // 4