ES6 JS - Notes

ES6 JS - Notes

Variables:

ES5

var myVar = "Leonardo";
In ES5 variables are function-scoped

ES6

let myVar = "Leonardo;
const myConst = 1996;
In ES6 variables are block-scoped. This means that my vars are only accessible in the block scope, like an if, for, while, etc.

--------------------------------------------------------------------------------------------------------------------------------

Blocks and IIFEs:

In ES5, IIFEs are used to allow us to encapsulate our variables and methods. Now in ES6, we can do the same just using { //**// }.
And it's possible because ours variables are block-scoped.

--------------------------------------------------------------------------------------------------------------------------------

Strings:

The biggest difference in ES6 to ES5 is the tamplate strings.

ES5

var name = "leonardo";
var age = 22;

var fullInfo = "This is " + name + " and he's " + age + " years old";

ES6

const name = "leonardo";
let age = 22;

let fullInfo = `This is ${name} and he's ${age} years old`;

new string methods:

const lastName = "steil";

const n = `${name} ${lastName}`;
console.log(n.startsWith("l"));
console.log(n.endsWith("il"));
console.log(n.includes("il"));
console.log(lastName.repeat(5));