Do you want to develop dynamic and interactive web applications? If so, ReactJS is your ultimate solution. ReactJS presents optimal solutions to some of the most persistent front-end programming issues. It's scalable, flexible, fast, powerful, and acquainted with an ever-growing robust Reactjs developers community.

This popular JavaScript library is being used by developers worldwide to build highly performant, maintainable, and scalable web applications. There has never been a better time to grasp the intricacies of ReactJS. 

This article will teach you five key concepts of ReactJS to understand how it works.

What is ReactJS?

ReactJS is a front-end library that helps in building user interfaces using multiple components. Facebook created ReactJS, and now it's maintained by a large community of developers. 

Remember that it's not a framework like Angular or Ember, where some decisions are already made for developers. Instead, it's a library wherein the React JS development company or developers need to make all the decisions. 

Expressions in JSX

JSX is a syntax extension for JavaScript that allows developers to write HTML-like, easy-to-read, and understand codes in their JavaScript files. Developers offering React JS development services can include JavaScript expression via a pair of curly brackets anywhere within JSX. 

For compiling the code, a JSX expression must include one outermost element. SX – a syntax extension of JavaScript is used to create DOM elements that are further rendered in the React DOM. It's necessary to compile a JavaScript file containing JSX before it reaches a web browser. 

React Virtual DOM

When you hire reactjs developers, you might commonly come across the term ‘Virtual DOM.' 

The virtual DOM is basically the real DOM's virtual representation. Every time the state of your application changes, the virtual DOM will get updated rather than the real DOM. 

You might think the virtual DOM is doing the same thing as the real DOM. So, how can updating the virtual DOM be faster than updating the real DOM? 

When a developer adds new elements to the UI, a virtual DOM (represented as a tree) is created. Each element will be displayed as a node on this tree. Whenever there is a change in the state of any of these elements, a new virtual DOM tree will be created. This tree is then compared with the previous virtual DOM tree. 

Finally, the virtual DOM determined the best possible method to make these changes in the real DOM. It will ensure minimal operations on the real DOM, minimizing the performance cost of updating the real DOM.

How does ReactJS use Virtual DOM?

In ReactJS, every UI piece serves as a component that has a state. ReactJS monitors the observable pattern and listens for state changes. Whenever there is a change in the component's state, ReactJS updates the virtual DOM tree and then compares it with the previous version of the virtual DOM. 

This comparison allows ReactJS to know which virtual DOM objects have been changed and, thus, updates only those objects in the real DOM. 

Props in JSX 

Props or properties are used to pass data from one component to another. A React JS development professional should know that props are read-only and, thus, can't be modified by the child component. To pass props to a component, developers need to add them as attributed to the component. 

Conclusion

ReactJS is a cutting-edge tool for building dynamic user interfaces. You should hire dedicated reactjs developers who understand these concepts. Such developers will be of great help in developing robust React applications.