Express API - Introduction

What is Express?

Express is a popular and widely-used web application framework for Node.js. It provides a fast, minimal and flexible way to build web applications and APIs. Express makes it easy to manage all aspects of the application development process, from routing and middleware to handling requests and responses.

Getting Started

To create an Express application, you need to have Node.js and npm (Node Package Manager) installed on your system. To check if you have them installed, open your terminal window and type:

node -v
npm -v

If you don't have Node.js and npm installed, you can download them from the official website.

Once you have Node.js and npm installed, you can create an Express application by running the following commands:

mkdir myapp
cd myapp
npm init
npm install express --save

This creates a new directory called myapp and initializes it with a package.json file. It then installs the Express framework and saves it as a dependency in the package.json file.

Creating a Simple API

Let's create a simple API using Express. Create a new file called index.js in the myapp directory, and add the following code:

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

app.get('/', function(req, res) {
  res.send('Hello World!');
});

app.listen(3000, function() {
  console.log('Example app listening on port 3000!');
});

This code creates a new Express application, sets up a route for the root URL / and sends a response of Hello World!. It then listens for incoming connections on port 3000.

To run this code, type the following command in your terminal:

node index.js

This starts the server and prints the message Example app listening on port 3000! to the console. You can now visit the URL http://localhost:3000 in your web browser to see the Hello World! message.

Conclusion

This was a brief introduction to Express and how to create a simple API with it. Express is a powerful framework that provides numerous features for web application development. For more information, check out the official Express documentation. Happy coding!

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