What are Hooks in React?

React Hooks open up a completely new approach to constructing functional components, enabling us to include capabilities like stateful logic that are only available for class components.

React mostly makes use of its built−in hooks, useState and useEffect Hooks, to do this. These hooks j

In this article, we will go over what hooks are and how they can be used to create applications with React. We will also see how they simplify everyday development workflows.

All About React Hooks

As quoted by team React−

  • “React Hooks are a new feature of React.js that makes it possible to use state and other React features without writing a class.”

They simplify the way we use React.js by removing the need for class components and render methods, and instead enable us to use functions as hooks.

They were announced at the end of 2018 with version 16.7 of React and were officially released in version 16.8, which was released in March 2019.

React Hooks act as a replacement for the class system. It is an alternative approach to React’s component model that allows us to avoid unnecessary abstraction and to provide an alternative way of handling stateful logic that doesn't require inheritance or higher−order components (HOC).

They eliminate the requirement to construct a class, which was the sole option in the past, and enable developers to access state and other React capabilities.

However, here are some general rules for hooks that every developer must keep in mind −

  • Hooks should be used in the topmost scope of the code and never to be used within loops, conditions, or nested functions.

  • Hooks should only be used by React function components.

  • Don't use ordinary JavaScript methods to call Hook

Note  These rules are also applicable for custom hooks.

React Built−in Hooks

React has built−in hooks, i.e., useEffect and useState, that allow developers to use code snippets to handle events or data updates.

Though, you can also reuse the stateful behaviour among components by creating custom hooks. Let’s first see a little more about these built−in hooks.

  • useState Hook

    The useState hook is used for storing a state within a component.

    The useState hook allows you to store and access state inside a component without using this.state or this.setState(). The state object can be passed down from the parent component to the child component via props, or it can be set directly on the child component with the useState hook.

  • useEffect Hook

    For side effects like obtaining data from an API or storing it locally, we use useEffect hook.

    It gives function components the ability to perform side effects, resulting in accomplishing the same thing that componentDidMount, componentDidUpdate, and componentWillUnmount do in React classes, but with a single API.

What are "custom hooks"?

Using custom hooks is an effective option in a case where we want to implement the derived functionality of both the useState and useEffect Hooks across many components.

We can simply reuse stateful behaviour across several components using custom React Hooks in a style that is both efficient and scalable. Additionally, custom hooks result in a clear and organized codebase, which lessens complexity and duplication in your React project.

As long as they adhere to the React Hooks standards, you are free to develop whatever custom hook you want to handle various logical scenarios.

Benefits with React Hooks

In React, hooks address a wide range of issues that at first glance seem unrelated to those we have faced over the course of five years of creating and maintaining tens of thousands of components.

You could be familiar with some of these issues whether you're studying React or perhaps working with a different framework with a similar component architecture.

We’ll see the difficulties that have been overcome by the introduction of hooks here.

Easy−to−understand complex components

In the past, the developers had to maintain parts that at first were straightforward but eventually turned into an unmanageable jumble of stateful logic. As a result, getting errors and inconsistencies became a normal thing. Instead of requiring a split based on lifecycle methods, hooks allow you to divide a single component into separate functions based on how its constituent parts are related.

Reduced Complexity without Classes (with functions!)

Learning React can be quite difficult because of classes. Props, state, and the downward data flow are concepts that people can grasp very well, but still have difficulty understanding in classes. Even among seasoned React developers, arguments over the distinction between function and class components can be seen frequently.

Contrarily, hooks allow you to embrace functions and use more React capabilities without the need to understand intricate functional or reactive programming techniques.

Easy to reuse Stateful Logic

You can remove stateful logic from a component using hooks so that it can be tested separately and used again. You can reuse stateful logic with hooks without altering the component structure which was very difficult earlier even the higher−order components and render props couldn’t manage to do it.

Sharing Hooks amongst numerous components or with the community is now way too simple.

Bottom Line

React's way of extending the component model with features that can be shared among all components.

In a nutshell, hooks have greatly increased our ability to develop flexible React applications, reducing the need for class−based components. React also offers some additional hooks that you can use to enhance the functionality of these hooks and produce even more incredible hooks on your own.