javascript Copy Code Copied // greet.js module . exports = function greet ( name ) { console . log ( </span><span class="token template-string" style="color: rgb(163, 21, 21);">Hello, </span><span class="token template-string interpolation interpolation-punctuation" style="color: rgb(57, 58, 52);">${</span><span class="token template-string interpolation">name</span><span class="token template-string interpolation interpolation-punctuation" style="color: rgb(57, 58, 52);">}</span><span class="token template-string" style="color: rgb(163, 21, 21);">!</span><span class="token template-string template-punctuation" style="color: rgb(163, 21, 21);"> ) ; } ; You can then require and use this module in another file:
javascript Copy Code Copied const MongoClient = require ( ‘mongodb’ ) . MongoClient ; MongoClient . connect ( ‘mongodb://localhost:27017/mydb’ , ( err , client ) => { if ( err ) { console . error ( err ) ; } else { console . log ( ‘Connected to MongoDB’ ) ; client . close ( ) ; } } ) ; You can perform CRUD (Create, Read, Update, Delete) operations using the MongoDB Node.js driver.
javascript Copy Code Copied const fs = require ( ‘fs’ ) . promises ; async function readFile ( ) { try { const data = await fs . readFile ( ‘example.txt’ ) ; console . log ( data . toString ( ) ) ; } catch ( err ) { console . error ( err ) ; } } readFile ( ) ; Node.js has a vast ecosystem of packages and libraries that can be easily installed and managed using npm (Node Package Manager). In this section, we’ll explore how to create and manage Node.js modules and dependencies. Creating a Node.js Module A Node.js module is simply a JavaScript file that exports a set of functions or variables. Here’s an example of a simple Node.js module: node.js beyond the basics pdf
bash Copy Code Copied npm install mongodb Here’s an example of how to connect to a MongoDB database:
javascript Copy Code Copied const fs = require ( ‘fs’ ) ; fs . readFile ( ‘example.txt’ , ( err , data ) => { if ( err ) { console . error ( err ) ; } else { console . log ( data . toString ( ) ) ; } } ) ; Promises provide a more elegant way to handle asynchronous operations. A promise represents a value that may not be available yet, but will be resolved at some point in the future. javascript Copy Code Copied // greet
Whether you’re building a complex enterprise application or a simple web API, Node.js provides a powerful and flexible platform for building fast, scalable, and efficient server-side applications.
bash Copy Code Copied npm install express You can also specify dependencies in your package.json file: MongoClient ; MongoClient
javascript Copy Code Copied const MongoClient = require ( ‘mongodb’ ) . MongoClient ; MongoClient . connect ( ‘mongodb://localhost:27017/mydb’ , ( err , client ) => { if ( err ) { console . error ( err ) ; } else { const db = client . db ( ) ; const collection = db . collection ( ‘users’ ) ; // Create collection . insertOne ( { name : ‘John Doe’ , age : 30 } , ( err , result ) => { if ( err ) { console . error ( err ) ; } else { console . log ( ‘User created’ ) ; } } ) ; // Read collection . find ( { } ) . toArray ( ( err , users ) => { if ( err ) { console . error ( err ) ; } else { console . log ( users ) ; } } ) ; // Update collection . updateOne ( { name : ‘John Doe’ } , { $set : { age : 31 } } , ( err , result ) => { if ( err ) { console . error ( err ) ; } else { console . log ( ‘User updated’ ) ; } } ) ; // Delete collection . deleteOne ( { name : ‘John Doe’ } , ( err , result ) => { if ( err ) { console . error ( err ) ; } else { console . log ( ‘User deleted’ ) ; } } ) ; client . close ( ) ; } } ) ; In this article, we’ve explored advanced concepts, techniques, and best practices for building scalable and efficient Node.js applications. We’ve covered asynchronous programming, Node.js modules and dependencies, and interacting with MongoDB.