How to Convert a Class Based Component to a Functional Component in React.js

Learn how to efficiently transform class-based components into functional ones in React.js, with practical examples and guidelines.
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Converting Class Based Components to Functional Components in React.js

React.js is a widely-used JavaScript library for building user interfaces. One of the major updates to React introduced the ability to create functional components with hooks, making them a popular choice for developers. If you're working on a project that uses class-based components but needs to switch to functional components, you may face some challenges. This guide will walk you through the process of converting a class-based component to a functional one, using an example from a sidebar menu in Material UI.

The Problem

You may have encountered a situation where you have a class-based component, and you want to leverage the benefits of functional components, such as cleaner syntax and easier state management with hooks. For instance, you might have a sidebar menu implemented in a class and want to migrate it into a function-based structure. However, during the conversion, you see that some functionalities, like the click event on a button, may not work as expected. This can be frustrating!

The Original Class Based Component

Here's a typical example of a class-based component in React that manages a sidebar menu:

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Converting to a Functional Component

To convert the above NavBar class component into a functional component, you will need to make a few changes. Here’s how you can do it step-by-step:

Step 1: Importing Hooks

You will want to use the useState hook to manage the state instead of using the class-based state.

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Step 2: Declaring the Functional Component

Define the functional component and its state.

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Step 3: Implementing Toggle Function

Use the useState hook to define the toggle function for the drawer.

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Step 4: Render the Component

Change the return statement to render the component just like the class version, but using functional syntax.

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Step 5: Export the Functional Component

Lastly, export the component just like you did with the class.

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Conclusion

By using React hooks, we can efficiently convert class-based components into functional components while maintaining the same functionality. The functionality of the button to open and close the drawer now works seamlessly in the new functional component structure. Remember, the key elements to focus on during conversion are the use of hooks for state management and ensuring the event handlers are correctly structured. Happy coding!