JavaScript Functions

React - Components

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Shivansh Rawat
·

3 min read

What is React?

React is a JavaScript library for building user interfaces. It was developed by Facebook and is often used for building single-page applications and mobile applications.

One of the main benefits of React is that it allows developers to create reusable UI components. This means that if you have a piece of UI that you want to use in multiple places in your application, you can create a single component for it and reuse that component as many times as you want. This can make it easier to develop and maintain complex applications.

React also uses a virtual DOM (a lightweight in-memory representation of the actual DOM) to improve performance. When a component's state changes, React updates the virtual DOM and then uses a diffing algorithm to determine the most efficient way to update the actual DOM. This means that you don't have to worry about manually updating the DOM or worrying about the performance implications of doing so.

Finally, React uses a syntax called JSX, which allows you to write HTML-like code in your JavaScript files. This can make it easier to understand and work with your UI code, as you don't have to switch between different files or languages.

Components in React

In React, a component is a piece of code that represents a part of a user interface. It can be either a function or a class, and it is responsible for rendering some HTML code that will be displayed in the browser.

Components are the building blocks of a React application, and they can be reused throughout the app to create a consistent look and feel. They can also be nested inside other components, allowing you to create complex UIs by combining simple components.

Types of Components in React

There are two main types of components in React: functional components and class-based components.

  • Functional components are simple functions that accept props as an argument and return a React element. They are easy to write and test, and are suitable for simple components that only need to render some HTML. Here is an example of a functional component:
import React from 'react';

function MyComponent(props) {
  return <h1>Hello, {props.name}!</h1>;
}
  • Class-based components, on the other hand, are JavaScript classes that extend the Component class from the React library. They have their own state and lifecycle methods, which makes them more powerful and flexible than functional components. Here is an example of a class-based component:
import React, { Component } from 'react';

class MyComponent extends Component {
  render() {
    return <h1>Hello, {this.props.name}!</h1>;
  }
}

In addition to these two types of components, there are also other variations, such as pure components and stateless functional components. However, functional and class-based components are the most commonly used types in React.

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