reactjs
  1. reactjs-introduction
PreviousNext

Introduction to ReactJs

ReactJs is a popular JavaScript library used for building user interfaces (UIs). It was developed by Facebook in 2011 and is currently being maintained by Facebook and the open-source community. ReactJs utilizes a component-based architecture which allows developers to break their UI into smaller, reusable pieces.

Syntax

To get started with ReactJs, you will need to import it into your code. This can be done by adding the following line at the beginning of your JavaScript file:

import React from 'react';

To create a new React component, you can use the following syntax:

function MyComponent() {
  return (
    <div>
      <h1>Hello, World!</h1>
    </div>
  );
}

This example creates a new component called MyComponent that returns a simple HTML element.

Example

Let's create a simple React component that displays a title and a button. Clicking the button will change the title to a new message.

import React, { useState } from 'react';

function App() {
  const [message, setMessage] = useState('Hello, World!');

  function changeMessage() {
    setMessage('Welcome to ReactJs!');
  }

  return (
    <div>
      <h1>{message}</h1>
      <button onClick={changeMessage}>Click me!</button>
    </div>
  );
}

export default App;

Output

When you run the example above, you should see a webpage with a title that says "Hello, World!" and a button that says "Click me!". Clicking the button will change the title to "Welcome to ReactJs!".

Explanation

In the example above, we start by importing the useState hook from React. We use the hook to create a new state variable called message, which we initialize to "Hello, World!".

Next, we define the changeMessage function, which will be called when the button is clicked. This function sets the message variable to "Welcome to ReactJs!".

Finally, we create the App component, which returns a div element with the message variable displayed inside an h1 element, and a button that calls the changeMessage function when clicked.

Use

ReactJs is used to create interactive user interfaces for web applications. It allows developers to create reusable components that can be combined to create complex UIs.

ReactJs is often used with other libraries and frameworks such as Redux, GraphQL, and React Native.

Important Points

  • ReactJs is a JavaScript library for building user interfaces
  • ReactJs uses a component-based architecture
  • ReactJs is maintained by Facebook and the open-source community
  • ReactJs is often used with other libraries and frameworks
  • ReactJs allows developers to create reusable components

Summary

ReactJs is a popular JavaScript library used for building user interfaces. It uses a component-based architecture and is maintained by Facebook and the open-source community. ReactJs allows developers to create reusable components that can be combined to create complex UIs.

ReactJsInstallation
Published on: