Differences between Functional Components and Class Components in React

React is a popular library for building user interfaces. It provides two types of components: functional and class components. Both types of components serve the same purpose, but there are some differences between them.

Introduction

React components are the building blocks of a React application. They are reusable pieces of code that are responsible for rendering a part of the UI. Components can be written in two ways: as functional components or class components.

What are Functional Components?

Functional components are the simplest type of components in React. They are functions that return a piece of UI. Functional components do not have state or lifecycle methods. They are pure functions that take props as input and return JSX as output.

Syntax of Functional Components

function MyComponent(props) {
  return (
    <>
      <h1>{props.title}</h1>
      <p>{props.content}</p>
    </>
  );
}

What are Class Components?

Class components are more complex than functional components. They are defined as classes that extend the React. Component class. Class components have state and lifecycle methods.

Syntax of Class Components

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    };
  }
  render() {
    return (
      <div>
        <h1>{this.props.title}</h1>
        <p>{this.props.content}</p>
      </div>
    );
  }
}

Differences between Functional Components and Class Components

State

Functional components do not have state. If you need to store state in a functional component, you need to use a state hook. Class components have state built into them.

Lifecycle Methods

Functional components do not have lifecycle methods. If you need to use lifecycle methods, you need to use a lifecycle hook. Class components have lifecycle methods built into them.

Performance

Functional components are generally faster than class components. This is because they do not have the overhead of creating a class instance.

Code Complexity

Functional components are simpler and easier to read than class components. They have less boilerplate code and are more concise.

When to Use Functional Components

Functional components should be used when you do not need state or lifecycle methods. They are also useful for writing reusable and composable code.

When to Use Class Components

Class components should be used when you need to store state or use lifecycle methods. They are also useful for writing complex UI logic.

Conclusion

Functional components and class components are two types of components in React. Functional components are simpler and easier to read, but they do not have state or lifecycle methods. Class components are more complex and have state and lifecycle methods built into them.

The choice between functional components and class components depends on the specific use case.

Thank You