Building Your First Express App: A Quick Guide

Introduction:

Express.js is a handy framework for building web applications using Node.js. If you're new to web development, creating your first Express app is a great way to start. In this guide, we'll walk you through the steps to create a simple Express app.

Prerequisites:

Before you begin, make sure you have Node.js installed on your computer. You can download it from the official website (https://nodejs.org/). Also, choose a text editor like Visual Studio Code, Sublime Text, or Atom.

Setting Up Your Project:

1. Create a Project Folder: Open your terminal and make a new folder for your project:

    mkdir my-express-app
    cd my-express-app
   

2. Initialize Your Project: Run this command to set up your project:

    npm init -y
   

   This creates a package.json file with default values.

3. Install Express: Install Express as a dependency:

    npm install express
   

Creating Your Express App:

1. Create an Entry Point: Inside your project folder, create a file named app.js.

2. Set Up Your Express App: Open app.js in your text editor and add:

    const express = require('express');
    const app = express();
    const port = 3000;
   

3. Create a Basic Route: Define a simple route that responds with "Hello, Express!":

    app.get('/', (req, res) => {
      res.send('Hello, Express!');
    });
   

4. Start the Server: Add this code to start the Express server:

    app.listen(port, () => {
      console.log(`Server is running on http://localhost:${port}`);
    });
   

Run Your Express App:

In the terminal, run:

node app.js

Visit http://localhost:3000 in your browser to see "Hello, Express!".

Conclusion:

You've successfully created your first Express app! This is just the beginning. Explore the Express.js documentation for more advanced features and best practices. Happy coding!