how to write a basic api using express js

To write a basic API using Express.js, you can follow these steps:

  1. Install Express.js: Begin by installing Express.js in your project. You can do this by running the following command in your terminal: npm install express

  2. Import Express: In your JavaScript file, import the Express module using the require keyword: javascript const express = require('express');

  3. Create an instance of Express: Initialize an instance of the Express application by invoking the express function: javascript const app = express();

  4. Define Routes: Define the routes for your API using the various HTTP methods (GET, POST, PUT, DELETE, etc.). For example, to create a GET route that returns "Hello World!" when accessed, you can write the following code: javascript app.get('/', (req, res) => { res.send('Hello World!'); });

  5. Start the Server: Start the server to listen for incoming requests by calling the listen method on the Express application instance. Specify the port number on which your server should listen. For example, to start the server on port 3000, use the following code: javascript app.listen(3000, () => { console.log('Server started on port 3000'); });

  6. Test the API: You can test your API by accessing the defined routes in your web browser or using tools like Postman. For example, if you defined a GET route for "/", you can access it by navigating to http://localhost:3000/ in your browser.

These steps outline the basic process of creating an API using Express.js. Remember to handle errors, parse request bodies, and handle other advanced functionalities as per your requirements. Express.js documentation provides detailed explanations and examples for further reference.