ES6 way of coding Javascript!

JavaScript is an incredibly fast and efficient programming language to use for a variety of purposes. Today Every type of software uses JavaScript, including Web apps, 3D games, robots, IoT devices, etc.

Back in 2007, Jeff Atwood (founder of StackOverflow), made a case that JavaScript would become a bigger part of web development. Atwood coined the term Atwood’s Law, which states:

Any application that can be written in JavaScript, will eventually be written in JavaScript.

It’s now ten years later, and Atwood’s statement is truer than ever. JavaScript is continuing to gain more and more adoption. The “next generation” of Javascript is something known as ES6. ES6 is so far the best and biggest update javascript has ever received. It streamlined the javascript development and almost killed jQuery's career. ES6 mainly allows you to write less code and do more.
In this post, I'll go over the six major differences between ES6 and ES5. Let’s take a look.

Arrow function: write less do more

ES5 WAY

function add(a,b){ 
    return a+b
}
console.log(add(2,3))
//OUTPUT: 5

ES6 WAY

const add = (a,b)=> a+b
console.log(add(2,3))
//OUTPUT: 5

---

Use const if you don't want to reassign the 'element variable by mistake.

ES5 WAY

var element = document.getElementById('myForm')

ES6 WAY

const element= document.getElementById('myForm')

---

De-structuring: write less do more!

ES5 WAY

var user = {
    name "Ritesh Kumar", 
    username: "@0xRitesh"
}
const name = user.name
const username user.username

ES6 WAY

var user = {
    name "Ritesh Kumar".
    username: "@0xRitesh"
}
const {name,username} = user

---

Template Literals

ES5 WAY

function getUsertMessage(name,country){
    console.log('Hi, my name is '+ name+ ',and I am from '+ country)
}
logUserMessage('Ritesh, 'India')

ES6 WAY

function logUserMessage(name,country){
    console.log(`Hi, my name is ${name}, and I am from ${country}`)
}
logUserMessage('Ritesh', 'India')

---

improve Object Literals

ES5 WAY

function getUserObj ( name, age, address){
    return {
        name: name,
        age: age,
        address: address
        }
}

ES6 WAY

function getUserObj ( name, age, address){
    return {
        name,
        age,
        address
        }
}

---

Default Parameters

ES5 WAY

function ES5Fun( username, platform){
    username, = username, || '@wordssaysalot';
    platform = platform || 'Dev';
}

ES6 WAY

function ES6Fun( username = '@wordssaysalot' , platform= 'Dev') {
}

Conclusion

Thanks for reading the article! I hope you guys found this article useful, and I hope I was able to introduce you to some of the ES6 features.

---

Comments

[Luke Shiru]

You have a few typos:

In "Arrow function: write less do more", ES6 is missing an =:

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

Also ideally you should show how it works with a single argument:

const add = a => b => a + b;

---

In "Template Literals" you used ' instead of using back-ticks:

const logUserMessage = (name, country) =>
    console.log(`Hi, my name is ${name}, and I am from ${country}`);

---

One last thing: You go back and forward between using new and old syntax. Ideally you should use arrow functions in all your examples.

Cheers!

[Supportic]

Sometimes for the sake of simplicity you don't want to use arrow function syntax.
E.g. event listeners, the reference of *this * comes in handy to reference the element. On the other hand you could also use event.target. My point is, arrow function syntax is not the holy grail.

[Luke Shiru]

If you write arrow functions inside classes, you can access this:

class Example {
    name = "Foo";
    greet = () => console.log(`Hello, ${this.name}!`);
}

And in plain objects you can still avoid writing function by using this syntax:

const example = {
    name: "Foo",
    greet() {
        console.log(`Hello, ${this.name}!`);
    }
};

Arrow functions aren't the holy grail, indeed ... but that doesn't mean that we need to use function everywhere either, that only means that we need to use it only when arrow functions don't work.

[Ritesh Kumar]

Thank you for pointing this up; it was a typo. and I've made the necessary changes.

[Revenity]

Remember: Arrow function does not have their own scope so use

const App = (name) => {
    this.name = name
}

this will be undefined in modules and window in page scripts

[Luke Shiru]

dev.to/lukeshiru/comment/1kmgb

[Patrick]

Dude he used backticks. Check well.

[Luke Shiru]

The post was updated after I made the comment 😅

[Lars Feldeisen]

Note for Arrow functions:

Arrow functions can be tricky when using it without declaration.

const runThis = (cb) => cb();
runThis(() => x+x);

Error would be:

VM1535:1 ReferenceError: x is not defined
    at <anonymous>:1:60.       <---------- ?
    at runThis (<anonymous>:1:35)
    at <anonymous>:1:47

But with declaration

const add = () => x+x;
runThis(add);

Looks like this:

VM1587:1 ReferenceError: x is not defined
    at add (<anonymous>:1:24) <---------- the function name
    at raise (<anonymous>:1:35)
    at <anonymous>:1:47
(anonym) @ VM1587:1

[ayaanraj]

Instead of this

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

it should be

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

[Bruno]

good read