React Hooks – Know Everything About It

React Hooks are a game-changing feature in the React library that started within it from version 16.8, after which classical practices began to change in building the React Application. 

What are React Hooks?

Rules

React Hooks are functions that let someone “hook into” the features of React—such as state and lifecycle methods—from functional components. It provides an occasion to reuse stateful logic between various components without those complex inheritance hierarchies or higher-order components.

Hooks are a solution to quite a few of the problems that most developers will have when working with React: the complexity of class components, the difficulty of reusing stateful logic between different elements, and the need for complex state management solutions. Hooks, developers are in a position to write more concise code, make better reuse of logic, and elevate testability—to enhance productivity and higher-quality React applications.

One of the most prominent advantages of Hooks is that it makes it easier to deal with state and lifecycle methods without class components. This will leave your code readable, maintainable, and easy to reason about when larger and more complex React applications are in question.

When to Use React Hooks

Any functional component may include React Hooks, but they are useful in the following cases:

• Stateful Functional Components: Hooks let you add state to functional components, which makes them powerful and versatile. This is very useful in managing the state in a component that doesn’t call for the complexity of a class component.
• Reusable Stateful Logic: Hooks make it easier to reuse the stateful logic between different components. Without building complex inheritance hierarchies or higher-order components. This will lead to more modular and maintainable code.
• Lifecycle Methods: Hooks give access to lifecycle methods, including the functional component’s componentDidMount, componentDidUpdate, and componentWillUnmount. This will enable doing side effects—like data fetching or subscription to events—in functional components more easily.
• Performance Optimization: They can be used to optimize the performance of your React application through memoization of their expensive computations. Or managing the lifecycle of resources. 

Also  Read  What is Virtual DOM in ReactJS

Types of React Hooks

React Hooks are available in different types with different purposes and use cases: 

1. React State Hooks

The simplest and most common one in use would be the useState Hook. It gives a way to provide functional components with a state. And offers a set of functions to deal with this state. This comes quite in handy, when handling simple states like counters, form inputs, or toggling states.

2. React Context Hooks

It can be used with React Context, which allows access to data across the component tree. Without having to explicitly pass props down from one level of the tree to the next. It is useful, especially when one wants to share data between multiple components. One could have easily done this without creating a class component or a higher-order component.

3. React Ref Hooks

The user hook returns a mutable reference, which is an object having a current property. Whose value will either be null when the component hasn’t mounted, or the current value has passed. This can be particularly useful in scenarios involving handling underlying DOM elements, managing focus, or just storing a value that is supposed to be retrieved over many renders.

4. Effect Hooks

The effect hook allows adding side effects, such as directly changing the DOM or fetching data from APIs, subscription to events, and other activities in functional components. Through this Hook, one is able to replicate class component lifecycle methods, including componentDidMount, componentDidUpdate, and componentWillUnmount.

5. React Performance Hooks

The useMemo and useCallback hooks memoize long computations and callbacks, respectively, for the improvement of a React application’s performance. What is more, these hooks show themselves especially useful in circumstances when you have components that execute some expensive calculations or when you want to pass callbacks down to child components.

6. React Resource Hooks

Finally, you can use LayoutEffect and ImperativeHandle to manage the lifecycle of resources in functional components. More specifically, these types of hooks are helpful if you want to ensure that some side effects run synchronously or if you need to expose an imperative API to the parent component.

7. More React Hooks

It also has a number of other hooks like useReducer, useDebugValue, and useTransition that resolve other more specialized issues. These hooks help in the management of complicated states, debugging information, or transitions between different states of UI.

Knowing and utilizing these different types of hooks will help you create powerful and efficient React applications that are easy to maintain and scale over time.

Also Read React Compiler: Everything You Need to Know

Benefits of using Hooks

Among the many advantages of using React Hooks, the most prominent are the following:

• Covering stateful logic for reuse: Hooks make it way easier to share stateful logic between different components without having intricate inheritance hierarchies or higher-order components hanging around. This will eventually result in greater modularity and maintainability of code since you’ll be covering and reusing stateful logic more successfully.
• Simpler Code: Hooks let you get rid of class components and their associated boilerplate, thereby making your code more concise and readable. It can help other developers spend time reading and working on the codebase, especially in larger and more complex React applications.
• Better Performance: One can memoize performance-expensive computations or deal with the lifecycle of resources using Hooks in React js application. A few of these features facilitate the delivery of user experiences that are faster and more responsive, which is a principle factor in the dynamic Web environment of today.
• Improved Testability: Hooks in react js allow for independent testing of your React components without having to establish any complex setup or mocking, hence better testability. The tests can also be written where the independent setup is much more reliable and maintains itself because changes in some other part of the application will not break that.
• More Flexibility: Hooks give a more flexible and modular way of building React applications since they are so easy to compose and combine in solving a wide range of problems. This makes adapting to changing requirements and evolving user needs easier.

Why the need to have ReactJs Hooks?

1. Use of ‘this’ keyword

The source of confusion and complexity within class components is this keyword, most especially when dealing with event handlers or lifecycle methods. Hooks eliminate this keyword, making such code pretty straightforward and easier to understand.

2. Reusable stateful logic

Hooks, sharing stateful logic between different components was problematic. It often required using higher-order component patterns or complex inheritance hierarchies. Hooks exposes a way to reuse stateful logic without these complex patterns. It leads to more modular and maintainable code.

3. Simplify complex scenarios

Class components can get complex and a pain to manage in cases where one is dealing with multiple lifecycle methods or state management. With hooks, the approach to building React applications is much easier and modular for handling difficult scenarios more easily and maintaining codebases over time much more manageable.

It’s in addressing these pain points that hooks have made doing a React application much easier to build and maintain. This has increased productivity with better quality code.

Rules of Hooks

Here are some rules of Hooks are:

• Only call Hooks at the top level: You should only call Hooks at the top level of your functional components or custom Hook. You should not call them inside loops, conditions, or nested functions.
• The rest of the rules ensure that you’re using Hooks correctly, and a component will continue to return the same elements once re-rendered. 
• Only call Hooks from React Functions: You can only call Hooks from React function components or custom Hooks, but not from regular JavaScript functions.
• Ensure the order of Hooks is constant across different renders of a single component. Hooks rely solely on the order during which you call them to determine them across successive re-renders.

Hooks usage in React

You simply need to import the desired Hook from the ‘react’ library. And use it in your functional component to be able to use Hooks in your React application.

Difference Between Hooks and Class Components

Hooks in React JS and class components can achieve similar results, they have some key differences.

• Syntax: Hooks use function components, class components are based on ES6 classes.
• State Management: Hooks use useState and useReducer, and the class component uses this. State and this.setState()
• Lifecycle Methods: Hooks functional usage useEffect incorporates side effects. This turns most of the lifecycle methods of the class component.
• Code Organization: With hooks, related logic is organized easily. In a class component, code is organized by lifecycle method.
• Reusability: The custom hooks are more convenient for reusing stateful logic written in class components.

Hooks in react js are a way to add state and lifecycle methods to functional components, making them more powerful and versatile through React course.

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