Mastering NodeJS with Interview Questions

Create your first Node.js program in JavaScript, write a simple console log, and run it with node in the terminal, using npm or yarn to manage packages.

Explore Node modules by creating, exporting, and importing functions across files. Learn using require, module.exports, and anonymous and arrow exports to modularize code and run examples.

Expose multiple Node.js functions by wrapping them in an object literal and exporting that object. Destructure the object to assign add, subtract, multiply, and divide for easy calls.

Master node debugging by using VS Code and Chrome DevTools to inspect and step through Node.js code, set breakpoints, and observe console output and variable changes.

Demonstrate how node exposes global objects without require, including the global object, module and module.exports, with __filename and __dirname revealing file name, path, and directory name.

Discover how to use the global setTimeout to run code after a delay, demonstrated with a start message and a 3-second timeout, and learn how to stop it with clearTimeout.

Cancel the timer created by setTimeout using clearTimeout by passing the timer instance and displaying a 'Timer cleared' message, while noting that setTimeout runs once and setInterval repeats tasks.

Learn how setInterval, a global object method, repeats a task at regular intervals in milliseconds, demonstrated by a counter incrementing every second and the option to stop with clearInterval.

Learn how to stop a running interval using the clearInterval global method by passing the timer object, stopping the counter at five with a conditional check.

Explore the node.js process global object, its lifecycle methods, and key properties such as argv, the node executable path, architecture, and memory usage, with practical demonstrations.

Explore the process argv property to handle command line arguments in node, access argv[2] for user input, and see practical examples with node and npm commands.

Explore node process event handling with process.on(), using events like before exit and exit to run callbacks and log messages during the process lifecycle.

Install chalk v4 to style the cli output with colors, bold text, and readable messages, including green success, yellow warning, and red error.

Explore the node os module to retrieve operating system details such as architecture, CPU info, hostname, platform, and free memory, using functions like os.freemem.

The lecture introduces the repl, or ripple, a read-eval-print-loop interface, to write and run node or javascript commands in the terminal.

Explore how JavaScript's single-threaded execution uses the call stack and event loop to manage synchronous and asynchronous tasks, including timers, the callback queue, and API calls.

Learn how buffers manage binary data in Node.js using the global buffer object, explore essential methods and encoding concepts, and prepare for file read and write operations.

Explore numeric systems and binary data basics, including bits, bytes, and conversions among binary, decimal, and hexadecimal, with 0x notation and practical CSS and C/C++ references.

Explore character sets and how binary data maps to text, focusing on Unicode and its 150,000 characters, and how ASCII and UTF-8 encode strings.

Explore buffers in Node.js, fixed-size memory containers that hold binary data, create with buffer.alloc, fill with buffer.write, and convert with buffer.toString using UTF-8.

Explore how Buffer.from() creates dynamic buffers in Node.js, contrasting with buffer.alloc's fixed size. See how strings like 'hi' and Node.js affect memory and output.

Store new values in a buffer with the fill method, create a buffer from a string, and see how a fixed seven-byte buffer hides the last character using bite length.

Explore the file system object, an internal fs module in node.js that creates, copies, renames, and deletes files and folders, and returns metadata with the stat method via a callback.

Learn how to check if a file or folder exists using fs.existsSync, which returns a boolean, and understand why exists is deprecated, with a command line example using index.js.

Learn how to read a text file with the fs readFile method, using a callback, observe a buffer, and convert it to a string to display the content.

Master the node fs writeFile method to write content to files by specifying the path, content, and options. Handle the callback to detect errors or confirm success after writing.

Explore the differences between readFile and readFileSync in Node.js, showing how asynchronous and synchronous file system operations read and write data, handle chunks, and manage callbacks.

Explore the fs.copyFile() method in Node.js, including src, destination, mode, and callback, with examples of copying text.txt, handling overwrites, and error cases when source or destination is invalid.

Create a Node.js program that copies a file using command line arguments via process.argv. Use fs.copyFile with source and destination, handle errors, and confirm when the file is copied.

Use fs.appendFile to append data to a file without overwriting, with encoding options, create new files if needed, and compare with fs.writeFile, which overwrites content.

Learn to use the read directory method to enumerate files and folders. See an example using fs.readDir and a callback that returns error and data for the node_modules directory.

Practice counting files and folders in a user-specified directory with a Node.js assignment that reads the directory from command line arguments using fs.readDir, and displays the total count.

Use fs.rename() in node.js to rename or move files with path, new path, and callback; it shows renaming text.txt to new.txt and moving it to parent folder with error handling.

Master node.js file deletion with fs.unlink by providing a path and callback, handling errors, and confirming success, including behavior when the file does not exist.

Compare readdir and readdirSync in NodeJS, showing how asynchronous reading with a callback can yield an empty array when logged prematurely, unlike the synchronous version that returns content immediately.

Mastering NodeJS with Interview Questions 2024 teaches creating folders with fs.mkdir, detailing syntax, path, options like recursive and force, and callback-based error handling for existing directories.

Discover how to delete folders with fs.rmdir() in node, including syntax, path, folder name, and the optional recursive option to delete non-empty directories.

Explore how web and mobile apps use servers to handle login requests and responses, and learn about Node.js http module and http/https protocols.

create a basic node server with the built-in http module and a request listener. run node app.js to listen on port 3000 and see the server running.

Explore the request object in Node.js by inspecting headers, url, and method to reveal client details, accepted response types, and how data flows with req.headers, req.url, and req.method.

Use nodemon to automatically restart the server on code changes, avoiding manual stops and restarts. Install it globally and run the server with node mon app.js to see automatic restarts.

Learn to handle HTTP responses in Node.js by using the response object to set the content-type header to text/html, write HTML, and end responses with res.end.

Define routes using request.url to serve the root and subsequent paths, deliver home page content for the root and json data for /data, and enforce a return to end responses.

Configure routes and send a JSON response by creating a product object, setting the content type to application/json, and using JSON.stringify to deliver the object at the /data route.

Create a getdate route in nodejs that returns the server date and time as a json object with the key now, using application/json and stringify to send the response.

Learn how get requests send data via the query string in the URL, demonstrated with a Node.js http server and a form with input fields and key-value pairs.

Configure the post method to submit data via /data, test routes, and implement conditional logic for post requests; compare data access in code module versus Express.

Receive post data using the http module's request object, accumulate chunks in a buffer, and convert them to a string for parsing key value fields.

Parse query strings in Node.js via the query string module and its parse method, returning a key-value object with a null prototype, and post form data to a file.

Post JSON data to a server and write it to a file using the fs module and writeFileSync, then read it with a get route, with Express.js simplifying http requests.

Compare the client and server work using the Http module with Express.js, noting Express.js's asynchronous, faster behavior and reduced development effort, then demonstrate installing Express with npm.

Create a server with express.js by importing express with require, creating an app via express(), and listening on a port (e.g., 3000) to run and handle requests.

Explain how express handles a get request by defining app.get with a route and a callback that uses req and res to inspect headers and remote ip.

Build a Node.js server that handles get requests, uses the response object to send or write HTML, and displays the request URL.

Learn how to set response headers to control content types in nodejs, switching between html and json responses and ensuring browsers render data correctly.

Define routes in Express.js using app.get for /products, handling request and response to serve HTML. Compare with the HTTP module, and learn to define multiple routes easily with Express.

discover how wildcard characters enable flexible routing in nodejs, using ? for optional characters, + for one or more, and * for any string in patterns like product-01 and product-*.

Explore how Express.js handles URL parameters by defining routes such as /user/:userId/:username, extracting values from request.params, and returning responses that display these parameters.

Master post requests in Express by using app.post to handle form submissions, read an HTML file with fs.readFileSync, and deliver it via response.send for the /data route.

Learn to read and display post request data using Express urlencoded middleware, wired with app.use to populate req.body and resolve undefined data.

Learn to use express.Router to create modular routes as mini applications, export them as modules, and mount with app.use for cleaner, readable Node.js routing.

Explore Postman as a fake client to test server APIs by sending get, post, put, patch, and delete requests, and learn installation options.

Execute get and post requests with Postman to test a server's root route, configure parameters and headers, and understand Postman's role in mocking a client for server-side development.

Explore put, patch, and delete requests, learning when to overwrite data versus update specific fields, and practice these methods with Postman in API development.

Use res.sendFile to serve HTML and image files with an absolute path. Handle cross-platform paths by combining dirname with path.join, ensuring dynamic server paths.

Configure express.static to serve css and image assets from a public folder using app.use and dirname, and understand why static serves entire folders over sendFile.

Middleware runs between request and response to perform checks. Use the next function to pass control along a chain of pre checks, including application or root level middleware.

Discover how to create a custom middleware in Express by defining a req, res, next function and wiring it with app.use to control request flow.

Create an express middleware that checks the request content-type and allows access only when it is application/json, otherwise returns an invalid request error.

Learn how to integrate the body parser middleware to parse request bodies, configure url encoded and json parsers, and handle form submissions in a NodeJS app.

Explore server side rendering with templating engines and compare CSR and SSR, analyzing how dynamic data is rendered on client versus server using engines like pug, handlebars, and ejs.

Master project scaffolding in NodeJS by building a mini store app with html, css, and templating engines to enable dynamic rendering with control statements.

Build a bootstrap-styled store interface with a nav bar and four product cards featuring an add to cart button and images, with custom css, then render and convert to pug.

Convert HTML to Pug using its simplified syntax, write attributes in parentheses, join classes with dots, use hash for ids, use div shorthand, and render with the templating engine.

Configure the Express app to use the Pug templating engine by setting the view engine to pug and designating the views folder, then render store templates with res.render.

Create a product page with a templating engine by building product.pug, reusing the navbar from store.pug, and adding a form to submit title and image to /new product via post.

Fetch submitted product data via a post endpoint, store it in a products array using body parser, and render the dynamic product list with title and img.

Export and import the products array, and pass it as an object literal to store.pug via response.render. Loop with each in to render dynamic product cards.

Use conditional rendering to show a no product available message and an add product button when the array is empty, linking to /new product; render product cards when products exist.

Reuse the navbar across pages by using a component based layout with Pug inheritance, extends, and block content to share the common interface, enabling templates in a layouts folder.

Learn to apply dynamic classes in pug templates with a selected page flag and a ternary operator. See how store and new product highlight as you navigate.

Install and configure handlebars with express, set .hbs templates, and build static and dynamic cards using iterative and conditional statements in handlebars templates.

Display user defined products with handlebars by looping the products array, using double curly braces to output this.title and this.img, and conditionally showing a no-products message with if/else.

configure a default main layout in handlebars to wrap every page with a top navigation bar, using the body placeholder wrapped in three curly brackets and enabling layout in app.js.

Install and set EJS as the Express templating engine, then build templates like store.js and new_product.ejs. Render dynamic content with for loops and conditional logic using EJS syntax.

Learn to build reusable interfaces in EJS using partials, mirroring components. Create an includes/navbar.ejs and render it with the include syntax using a hyphen to render HTML.

Set up a Node.js project, install Express and Nodemon, create index.js as the app entry point, and run an Express server on port 3000 while preparing to connect to MySQL.

Connect your node server to a MySQL database using mysql2, enabling create, read, update, and delete operations. Configure a connection pool, handle errors, and test queries to improve performance.

Establish a connection, then use pool.query() in a callback to run a select star from products, handle errors, and log data in the console.

Insert a new product record using pool.query with id, product_name, and price, inspect the result set header for insertion details, and verify the record by running a select.

Demonstrate updating a product price with pool.query, and show that running the same query twice may match a row but not change it.

Delete records using the pool.query method by crafting a delete from products where id equals a value, while handling errors, logging results, and verifying affected rows.

Mastering NodeJS with interview questions 2024 explains using pool.execute for safer queries to prevent SQL injection, by passing the query and a callback, as shown with a products table select.