React Tutorial 1

 ES6 introduced classes.

A class is a type of function, but instead of using the keyword function to initiate it, we use the keyword class, and the properties are assigned inside a constructor() method.

A simple class constructor:

class Car {
  constructor(name) {
    this.brand = name;
  }
}

Notice the case of the class name. We have begun the name, "Car", with an uppercase character. This is a standard naming convention for classes.

Class Inheritance

To create a class inheritance, use the extends keyword.

A class created with a class inheritance inherits all the methods from another class:

The super() method refers to the parent class.

By calling the super() method in the constructor method, we call the parent's constructor method and gets access to the parent's properties and methods.

Arrow Functions

Arrow functions allow us to write shorter function syntax:

Before:

hello = function() {
  return "Hello World!";
}

Try it Yourself »

With Arrow Function:

hello = () => {
  return "Hello World!";
}

Try it Yourself »

     It gets shorter! If the function has only one statement, and the statement returns a value, you can remove the brackets and the return keyword:

Arrow Functions Return Value by Default:

hello = () => "Hello World!";