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What Is React and Why Use It? (Complete Guide)

If you’ve been considering becoming a web developer or if you’re getting deeper into learning about coding, you may have heard of React JS. So, what is React? How should you use it, and why? 

React JS isn’t another coding language like Python or CSS. It’s something entirely different. 

In this article, we’re going to help you understand React JS and how it can be an essential part of your tool kit as a web developer. We’ll cover the following:

  • What Is React JS?
  • What is React used for?
  • React’s main features and components
  • Why you should use React
  • The best ways to learn React JS

Let’s dive in!

What Is React JS (React JavaScript)?

To understand React JS, you need to understand a bit about JavaScript itself. That’s what the ‘JS’ stands for, after all!  

We’ve got a whole article about JavaScript you can read, but here’s a quick synopsis: JavaScript is a programming language that facilitates interactions between the website you build and the computer of the person visiting the site. JavaScript can help you make adjustments to every single part of a website, from the visual look of the site to how the page relays information to the user.

Because so many of JavaScript’s most important functions are repetitive, developers created libraries of these functions to store the information needed to complete the tasks without having to recreate the code repeatedly. React JS is one of these libraries – and it’s very robust! 

What Is React Used For?

React JS is a JavaScript library used for building user interfaces (UIs) for single-page applications. React manages the view layer and is used for the development of both web and mobile applications.

Created by a Facebook developer named Jordan Walke, React is one of the most widely used libraries, primarily because of its open source nature; over 1000 web developers have now contributed to this robust library. It’s so widely used, it’s actually the go-to library for Uber, Facebook, Instagram, Amazon, Twitter, Netflix, and more than 8700 other industry-leading companies and brands. 

The Main React Features

Besides being an open-source program, React has features that make it an indispensable part of your web developer toolkit. Here are a few of its most useful features:

JSX (Javascript Syntax Extension)

JSX is a syntax extension to use alongside JavaScript. It allows the developer to include easy descriptions that resemble an HTML template. JSX looks like markup and can be so simple it looks like a template language. However, it functions with the full power of JavaScript.

VDOM (Virtual Document Object Model)

To understand the power of Virtual DOM, you should know that prior to this useful application, a change in the interface required the entire interface code to be rewritten. This was lengthy and slowed down load speed and created a sluggish interface. However, with a VDOM, your site has a virtual representation of the actual UI. When changes are made, the VDOM compares the new UI to the existing UI and makes changes to the DOM only where necessary. This creates a much faster application and doesn’t waste memory.

The Main React Components

React components are another reason developers flock to React. React JS is a simple library built on the concept of simple component design. You can think of components like Lego bricks. You can build something very simple, or you can use simple designs to create things that are more complex.

You can write code in React either as a class or a function. 

React Class Components

Class components make up the foundation of most modern apps that are built in React. These components are simple classes, made up of functions that add utility to the application. 

React Functional Components

React functional components are just JavaScript functions used in React JS. You can create your own functional components by writing a common JavaScript function.

Why Use React?

Now that you know a bit more about what React JS is, should you learn to use it? We think there are some great reasons to consider learning React.

It’s popular for a reason – actually, it’s popular for lots of reasons! Here are the top reasons we think you should learn React and use it in your web development.

  • Easy to Learn – If you have a firm grasp of JavaScript, you can learn React in a matter of months, and it can completely revolutionize how you design and create content for the web. 
  • Flexible – Once you’ve learned React, you can easily create functions that meet your needs. It’s incredibly flexible and can be customized to look, feel, and react exactly how you’d like it to.
  • Performance – Because of functions like VDOM, React JS allows you to optimize the performance of your websites and apps without sacrificing memory.
  • Data Binding – React uses unidirectional data flow, meaning the information only passes in one direction, from parent to child components. This makes functions you create on React much more stable.
  • Reusable Components – When you create something on React, the component you make can be reused in its complete form. Or, it can be slightly modified to look different while keeping its basic structure and functionality constant. This obviously saves a lot of time.
  • Easy to Test – React makes code easy to test, and because of its one-way data flow, created code can’t be accidentally changed down the road. This eliminates the need for repeated testing throughout the life of your build.

Learn React JS at Coding Dojo

If you’re considering learning React development, you can use Coding Dojo’s robust courses to learn quickly and feel confident you’ll have a firm foundation.

Our software bootcamp and other courses make sure you graduate with a full understanding of React JS among many other standard and helpful industry tools. You’ll learn React alongside Java, Python, and other leading programs and languages, and access live instruction, Discord peer groups, open TA hours, and a complete student services team.

Now is the perfect time to learn web and application development. Do you have questions? We’d be happy to speak to you, or you can attend one of our virtual open houses where you can meet our instructors, learn more about our curriculum, and save $100 on the cost of your course. Contact Coding Dojo to learn more about React coding!

React JS FAQ

Should I Learn React JS?

Yes! We believe learning React JS makes you more employable and can help you become a better overall web developer. React JS is flexible and stable, and its development systems are becoming more widely used across the web. Even if you aren’t directly using React, the more you develop for web, the more you’ll come across the fundamental principles and patterns of React being used across the internet.

What Are Props in React?

Props stands for properties in React. Keep in mind that React is a library, made up of smaller building blocks of reusable information called components. Most often, these components need to communicate data to one another. Props are how this information is passes.

What’s different about the props in React is that the information can only flow in one direction, from parent to child data. Any props data is also read-only which means it can’t be changed by a child component.

What Are Hooks in React?

React Hooks allow you to use state and other life cycle methods within function-based React components. Without understanding how to create class and functional components in React, Hooks can feel like a mystery, but the important thing to understand is that Hooks allow you to simplify your design by giving you the option to reuse the functions you’ve created. They allow you to use state and other React features without writing a new class.

What Is Render in React JS?

Rendering is simply the process of React gathering information about what the UI should look like, based on the combination of props and state you’ve used. During the rendering process, React will begin at the root of the component tree and move downwards, searching for updates that need to be made to the DOM. 

For each necessary change it discovers, React will flag it as either a class component or a functional component, then save the render output. After it has collected all the necessary output changes, a new component tree will be created on the VDOM. From here, it compiles a list of changes that need to be made to the DOM. Up until this point, this process is called the “Render Phase.”

React will then apply all of the changes in one sequence. This is known as the “Commit Phase.”

In Conclusion

React JS is a useful tool that will simplify your web development while saving you time, and making you a more nimble and versatile designer. We encourage you to learn more about this tool. Want to learn more about React? You can read about how React stacks up against similar tools like Angular.