Rendering Elements in ReactJs

Rubleen Kaur
Last Updated: May 13, 2022

Introduction

In the article, Introduction to JSX we have seen how to create elements in ReactJs. The elements in React are the smallest building blocks that can be rendered on the application.

In ReactJs, we have components that are built using different elements.

To make our elements perform functions, we need to render them in ReactJS, and this article describes how we can practice Rendering in React and use them accordingly. The first question that would pop up in your mind is what is rendering in React? Rendering in React is a process that gets triggered when there is a change of state in the components. Interested to learn more about React Components, do read the blog about it to understand better. 

An element in ReactJs is the smallest unit that we can render. 

Let’s see how we create an element in ReactJs.

const element = <h1>Hello, world</h1>;

 

Apart from different DOM browser elements, the React DOM takes care of the updation of parts after the app has been rendered.

ReactDOM.render() method

The ReactDOM.render() method takes two arguments, the HTML code and the HTML element to be rendered. This method is used to display the HTML code specified in the arguments. The render method is used to Rendering in React on the public folder where the index.html file is located in the folder. This makes our content visible on screen. 

In the context of the first example, when we used a single h1 statement rendered on screen, observe we had a small h1 code inside the index.html file, and the root element was updated using the ReactJs code. This explains how the ReactDOM.renders() method works. 

<div id="root"></div>

 

ReactDOM.render(<p>Explaining the ReactDOM.render method</p>, document.getElementById('root'));

 

OUTPUT

How to perform Rendering in React?

Let’s discuss Rendering in React using an example of a component and work our way accordingly in the article to render elements.

In the example we will consider a root id of an id tag and Rendering in React it accordingly, 

<div id="root"></div>

 

All the elements in this tag are considered as the root element in the React DOM. Everything in this div is regarded as a root. 

Most of the time, React Applications are built using a single root DOM, but when we try to integrate React into a pre-existing application, we can isolate as many root nodes as we want in the DOM.

For your reference, we have added an example below, 

const ele = <h1>Hello, Ninja</h1>;
ReactDOM.render(ele, document.getElementById('root'));

 

Using the above HTML and React code, the final output would be:

OUTPUT

Updation in ReactJs Elements(Rendering in React after updation)

One of the critical features of React DOM is that it compares the elements and their children to the previous values and only updates the DOM if there are changes applied. What would happen if we had rendered the elements once but performed the changes in the app? Will the app render itself again? 

Using Rendering in React, the events are immutable. This means that the DOM creates a new element for a recent change whenever a change is applied. To understand the concept better, go through the live clock code given below, 

function clock() {
  const element = (
    <div>
      <h1>Hello, Ninja</h1>
      <h2>It is {new Date().toLocaleTimeString()}.</h2>
    </div>
  );
  // highlight-next-line
  ReactDOM.render(element, document.getElementById('root'));
}

setInterval(clock, 1000);

 

 

OUTPUT

In the above code, we have used a few ReactJs methods. The ReactDOM.render() is called every second from the setInterval() callback. 

In the above example, we have seen that the ReactDOM.render() method renders the elements on the browser window, using two arguments(the HTML code and the HTML element). 

Frequently Asked Questions

What is the render() method in ReactJs?
Ans: The render() method in ReactJs is used to specify the content that is to be displayed on the website. It is used to describe the view which is finally rendered on the browser. The render method is also used to perform Rendering in React content on the public folder where the index.html file is located in the folder. This makes our content visible on screen. 

Does changing state re-render the React Application?
Ans: React components automatically re-render whenever we perform a change in the application’s state or props. A simple update of the condition causes the entire User Interface (UI) elements to be re-rendered automatically from anywhere in the code. This is done only by the render method provided by the ReactDOM. 

Can we have multiple ReactDOM renders?
Ans: Yes, we can have multiple renders using the ReactDOM. We can have multiple calls to ReactDOM. render() in a single JavaScript file without any issues. We can have multiple calls to ReactDOM. render() may be especially useful when using React in an existing application/site.

Key Takeaways

This article has covered all the essential information about Rendering Elements in ReactJS.he render() method in ReactJs is used to specify the content to be displayed on the website. It is used to describe the view which is finally rendered on the browser. The render method also renders our content on the public folder where the index.html file is located in the folder. This makes our content visible on screen. The article covers the ways using which we can Rendering in React the elements. It also explains the update of ReactJs Elements after the app is rendered. Did you have fun exploring ReactJs?

We have provided a fantastic Web Development course for you, and we feel it could be the perfect aid to make you better than the rest of the developers.  

 

Happy Learning Ninjas!

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