The react npm package is a JavaScript library for building user interfaces, particularly for single-page applications. It allows developers to create reusable UI components and manage the state of their applications efficiently.
Component-Based Architecture
React allows developers to encapsulate UI logic and design into components, which can then be composed to build complex user interfaces.
class Welcome extends React.Component {
render() {
return <h1>Hello, {this.props.name}</h1>;
}
}
ReactDOM.render(<Welcome name='Jane' />, document.getElementById('root'));State Management
React provides a way to manage the state within components, enabling dynamic and interactive user interfaces.
class Counter extends React.Component {
constructor(props) {
super(props);
this.state = { count: 0 };
}
increment = () => {
this.setState({ count: this.state.count + 1 });
};
render() {
return (
<div>
<p>{this.state.count}</p>
<button onClick={this.increment}>Increment</button>
</div>
);
}
}Lifecycle Methods
React components come with lifecycle methods that are invoked at specific points in a component's lifecycle, allowing developers to hook into the component's creation, updating, and destruction processes.
class Timer extends React.Component {
componentDidMount() {
this.timerID = setInterval(() => this.tick(), 1000);
}
componentWillUnmount() {
clearInterval(this.timerID);
}
tick() {
this.setState({
date: new Date()
});
}
render() {
return (
<div>
<h2>It is {this.state.date.toLocaleTimeString()}.</h2>
</div>
);
}
}Hooks
Hooks are functions that let developers 'hook into' React state and lifecycle features from function components. They provide a way to use stateful logic without writing a class.
import { useState, useEffect } from 'react';
function Example() {
const [count, setCount] = useState(0);
useEffect(() => {
document.title = `You clicked ${count} times`;
});
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
</div>
);
}Vue.js is a progressive JavaScript framework used for building user interfaces. Unlike React, which is only the view layer, Vue includes a more comprehensive set of tools for building web applications, including a routing solution and state management solution.
Angular is a platform and framework for building single-page client applications using HTML and TypeScript. Angular is more prescriptive than React, providing a standard way to structure an application and including a wide array of features out-of-the-box, such as dependency injection, templating, routing, and more.
Preact is a fast, 3kB alternative to React with the same modern API. It provides the thinnest possible Virtual DOM abstraction on top of the DOM. Preact is a good choice for when performance is critical, and the application needs to be as lightweight as possible.
Svelte is a radical new approach to building user interfaces. Whereas traditional frameworks like React and Vue do the bulk of their work in the browser, Svelte shifts that work into a compile step that happens when you build your app, resulting in significantly smaller and faster applications.
An npm package to get you immediate access to React,
without also requiring the JSX transformer. This is especially useful for cases where you
want to browserify your module using
React.
Note: by default, React will be in development mode. The development version includes extra warnings about common mistakes, whereas the production version includes extra performance optimizations and strips all error messages.
To use React in production mode, set the environment variable NODE_ENV to production. A minifier that performs dead-code elimination such as UglifyJS is recommended to completely remove the extra code present in development mode.
var React = require('react');
// You can also access ReactWithAddons.
var React = require('react/addons');
0.11.0 (July 17, 2014)
getDefaultProps() is now called once per class and shared across all instancesMyComponent() now returns a descriptor, not an instanceReact.isValidComponent and React.PropTypes.component validate descriptors, not component instancespropType validators should return an Error instead of logging directlynulle.key and e.getModifierState() propertiesonBeforeInput eventReact.Children.count has been added as a helper for counting the number of childrene.view properly normalizedcoords, crossOrigin, download, hrefLang, mediaGroup, muted, scrolling, shape, srcSet, start, useMap)className on a mounted SVG component now works correctlymask and tspandx, dy, fillOpacity, fontFamily, fontSize, markerEnd, markerMid, markerStart, opacity, patternContentUnits, patternUnits, preserveAspectRatio, strokeDasharray, strokeOpacityWebkit, ms, Moz, O) are now handled properlyimg event listeners are now unbound properly, preventing the error "Two valid but unequal nodes with the same data-reactid"$apply command to transform valuesdist/.envify is properly listed as a dependency instead of a peer dependency<Components.Checkbox />harmony features available in the command line with <script type="text/jsx;harmony=true">--harmony option--source-map-inline option to the jsx executabletransformWithDetails API which gives access to the raw sourcemap dataFAQs
React is a JavaScript library for building user interfaces.
The npm package react receives a total of 12,074,552 weekly downloads. As such, react popularity was classified as popular.
We found that react demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
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