What does React js do?

What does React js do?

Hey readers, we all know that React is by far the most popular library used in web development. But what does React js do? Why do people even use React? Continue reading this post if you want to get the solution to this question. Before answering, let’s have an introduction to React.

What is React?

It’s a JavaScript package that lets you make user interfaces and components for front-end apps. Meta is the company behind it (previously Facebook). It is frequently used to construct large-scale complex systems due to the concept of reusable components, state, props, hooks, redux, and simple architecture. It helps to render HTML code snippets that are used in web app development. Every time you submit an image on Instagram, for example, you get likes and comments. These “likes” and “comments” react components. React checks the component’s state and only renders the changed component. This is merely a small part of React’s front-end functionality. Let’s take a closer look at it and explain it in depth.

What does React js do?

The reason React was created in the first place was that the DOM in web applications is slow. In order to build scalable and efficient yet complicated web apps, developers realized they required a solution to this problem. During internal operations, React gives a much faster solution. It makes use of virtual DOM, which is a version of the DOM tree that is utilized to define a document’s logical structure. Whenever the DOM receives a read or writes event, it will invoke its virtual component, which will then choose the most effective method of updating the browser’s DOM. Unlike DOM elements, React elements are simple to construct and are basic objects. React DOM transforms the browser’s DOM into React elements. This occurs because the DOM tree is stored in the JavaScript element, which speeds up the process. React calculates and updates the browser using an in-memory data structure cache. This allows a unique feature that permits the programmer to code in such a way that the whole web page is rendered on every change whereas react library simplest renders components that really change.

React’s functionality is separated into two APIs:

  1. React DOM is primarily used in applications to render web pages.
  2. React component API- This is the actual page that React DOM API renders.

React components can now be divided into the following sections: 

  1. Data is information that a component renders. It makes no difference to React which component rendered this data.
  2. Lifecycle- These are methods that we use in React to changes in component lifecycles, such as when a component is going to be rendered.
  3. Developers write events, which are code snippets or functions that respond to user interaction.
  4. JSX is a shorthand for expressing React components’ UI structures.

React’s efficiency and scalability are due to the virtual DOM. But, in a React application, how does Virtual DOM function behind the scenes?

React’s Virtual DOM works in three steps:

  1. If the state or props change, the complete UI is re-rendered in the Virtual DOM.
  2. To understand the distinction between DOM and Virtual DOM, you’ll need to understand the diffing process, which will be described later.
  3. The DOM only updates those items that have changed after the change.

Features of React

  • It is Declarative and simple
  • It has Component-based architecture
  • Provides server-side rendering
  • Fast and extensive
  • It is easy to learn

Single way data flow in React

In React, data flow is one way only. Components are provided a collection of immutable values that are presented as HTML tag properties. The components cannot be modified directly, instead, a callback function is passed with which modification can be done, and this complete process is called “properties flow down and action flow up”.


Internally, React accomplishes this. If you’re interested in studying React js, codedamn offers classes with a built-in environment playground where you can learn and practice code. Join the codedamn community, read other programming and development articles on the site, and subscribe to our newsletter to stay up to date on new programs and upgrades. If you have any queries or suggestions, please post them in the comments section. Also, if you join up for codedamn, don’t forget to check out the referral section, copy your link, and refer as many people as possible to earn great gifts, merchandise, and prizes from codedamn.

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