ECMAScript 2015+ functionalities

In this topic, we will demonstrate how to use some of the functionalities of ES2015, which may be useful in everyday JavaScript coding and which will also be useful to simplify the examples presented in the following chapters of this book.

Among the functionalities, we will cover the following:

• Variables with let and const
• Template literals
• Destructuring
• Spread operator
• Arrow functions using =>
• Classes
• Modules

let and const instead of var

Until ES5, we could declare variables in any place in our code, even if we overwrote the variables declaration, as in the following code:

var framework = 'Angular'; 
var framework = 'React'; 
console.log(framework); 

The output of...