Everything is a Component

How do we Create Components? 💻

What are Components?

Lets hear what the creators of React have to say about components.

Components let you split the UI into independent, reusable pieces, and think about each piece in isolation.

Well that doesn’t provide much information! 😕

They really meant that:

• React components are the core building blocks of a React application that represent how a particular element would be visualized on the User Interface.

• Combining tens to thousands of components together makes up your application.

• A component must be designed in a way that makes it reusable across any page or even projects.

• A component may be responsible for performing a single task (if any).

A button or an input component for example has a single responsibility of allowing the user to perform an action or type input via their keyboard or keypad respectively.

React provides us with HTML elements as components out-of-the-box, they work and behave the same way as we expect them to work in HTML.

React provides us with two ways to create components:

1. ES6 Class

2. Functions

Both the techniques are responsible for returning a React element. These elements can then be used across various pages to define how the UI will be displayed to the end user.

Identifying Components 🔎

Class Component

Class components as its name suggests are created using the ES6 class syntax. The following snippet displays two ways of creating a component using the ES6 class syntax (follow which every you like, there is no benefit of using one syntax over the other).React component created using ES6 class syntaxReact component created using ES6 class syntax and named import statement

The code is simple to understand. Every class that extends the React.Component class is obligated to implement the render() method which returns a React element. This element is then applicable to be displayed on the User Interface.

Class components are also known as Stateful components.

import React, { Component } from 'react';

export default class Button extends Component {
  render() {
    return <button>Sign up</button>;
  }
}

Example time

Lets start by creating a simple button component such as the cool one shown above (just not with styles since that a complex topic to dive into and I don’t want your attention to drift away from components). The code for creating the uncool-unstyled-button is as:A button component implemented using ES6 class

See how simple it is to create a component. All you have to do now is use this component anywhere in your project and there you go, it renders on the user interface as you wanted it to.

Function Component

If the name wasn’t enough, a function component is created using a JavaScript function (anonymous, named, arrow). The following snippets displays three ways of creating a function component (again there are no perks of using one over the other).Function component using an anonymouse functionFunction component using a named functionFunction component using an arrow function

import React from 'react';

function paragraph(props) {
  return <p>This is a another paragraph component</p>;
}

export default paragraph;

A simple difference when compared with class components is that you don’t need the React.Component class to work with function components. The React element returned by the function is visualized on the User Interface.

Function components are also referred as Stateless components.