React js application modification after installation?

Modifying a React.js application after the initial installation involves making changes to its source code, adding or updating components, and managing dependencies. Here’s a step-by-step guide on how to modify a React.js application:

1. Navigate to Your React App’s Directory:

Use the terminal or command prompt to navigate to the directory where your React.js application is located.

cd your-react-app

2. Open the Project in Your Code Editor:

Open your React.js project in your preferred code editor. Common code editors include Visual Studio Code, Sublime Text, or Atom.

code .  # Use the appropriate command for your code editor

3. Modify Existing Components or Create New Ones:

Navigate to the src folder in your project directory. This is where your React components are stored. You can modify existing components or create new ones to add functionality or improve the user interface.

For example, open the App.js file and make changes to the component code:

// src/App.js

import React from 'react';

function App() {
  return (
      <h1>Hello, Modified React App!</h1>
      <p>Welcome to your modified React.js application.</p>

export default App;

4. Run Your React App Locally:

After making changes, run your React app locally to see the modifications. In the terminal, run:

npm start

Visit http://localhost:3000 in your web browser to view the updated React application.

5. Manage Dependencies:

If you need to add new dependencies or update existing ones, use the following commands:

  • To install a new dependency:
  npm install package-name
  • To update a dependency:
  npm update package-name

6. Commit Changes to Version Control (Optional):

If you are using version control (e.g., Git), commit your changes to track modifications and collaborate with others.

git add .
git commit -m "Modified React application"

7. Deploying Changes:

If your React application is hosted on a platform like GitHub Pages, Netlify, or Vercel, follow the deployment instructions to update the live version of your app.

8. Testing:

Before deploying changes to production, thoroughly test your application to ensure that the modifications work as expected and do not introduce any errors.

9. Documentation (Optional):

Update documentation to reflect any changes made to the application. This is especially important if others are working on the project or if you plan to share the code.

By following these steps, you can effectively modify and enhance your React.js application after the initial installation. Whether it’s tweaking the UI, adding new features, or updating dependencies, these steps provide a structured approach to managing and improving your React application.

If you want to modify the React js Application after installation then just go to myfirstreact after that go to src folder and just open the App.js file and modify that


The default React Application code will look like

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';

class App extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
            Edit <code>src/App.js</code> and save to reload.
            rel="noopener noreferrer"
            Learn React

export default App;

If you just want Hello World for React application then just remove the tag from the render return like

import React, { Component } from 'react';

class App extends Component {
  render() {
    return (
      <div className="App">
        <h1>Hello World</h1>

export default App;

Now your modification in React Application will appear after saving without having to reload in the browser

Now your First Hello World React js application is ready

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