ES5 vs ES6 in JavaScript

In this tutorial, you will learn about the difference between ES5 and ES6. ES5 and ES6 are JavaScript versions.

What is ES5?

ES5 is the full form of ECMAScript 5, and it was released in 2009.

ES5 introduced some features like

1. It has a strict mode
2. It has JSON support.
3. It has Array methods like map(), filter(), reduce().

Example of ES5 Function

function add(a, b) {
  return a + b;
}

What is ES6?

ES6 (ECMAScript 2015) was released in 2015, and It has Modern JavaScript.

ES6 introduced many features

1. let & const data types
2. Arrow functions
3. Classes
4. Promises
5. Modules
6. Destructuring

Example of ES6 Function

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

ES5 vs ES6 – Quick Comparison Table

Differences with Example

1. Use Variable

ES5

var name = "John";

ES6

let name = "John";
const age = 35;

2. Use Arrow Function

ES5

You use only the normal function in ES5

function welcome() {
  console.log("Hello");
}

ES6

const welcome = () => {
  console.log("Hello");
};

3. Use Template Literals

ES5

var name = "John";
var msg = "Hello " + name;

ES6

let name = "John";
const msg = `Hello ${name}`;

4. Use Classes

ES5

function Employee(name) {
  this.name = name;
}

ES6

class Employee {
  constructor(name) {
    this.name = name;
  }
}

5. Use Destructuring

ES5

var a = obj.a;
var b = obj.b;

ES6

const { a, b } = obj;

ES5 vs ES6 – Objective Questions (MCQs)