The most common is npm, but you can use others, such as Yarn or pnpm. Your interview will likely start with an introductory exploration of Node.js applications. You should be ready to describe the most common components and how to structure, add to, and export your application. Here are 20 of the most common interview questions on Node.js and some insights on preparing for them.
- During any test cases, stubs provide the canned answers of the functions.
- To include a module in a Node.js application, we must use the require() function with the parentheses containing the module’s name.
- These functions require a callback function to handle errors and process the result.
- Module.exports is a Node.js module that allows you to export objects, functions, and variables from your code.
- Yes, Node.js provides a simple TCP based protocol and built-in debugging client.
- It is the foundation of the non-blocking input/output in Node.js, making it one of the most important environmental features.
- The Punycode is an encoding syntax which is used to convert Unicode (UTF-8) string of characters to ASCII string of characters.
The reactor pattern is a concept of non-blocking I/O operations in Node.js. Through this pattern, we get the handler (or callback function) for each I/O operation. Each I/O request is submitted to a demultiplexer that handles concurrency and queues the requests/events.
Explain the difference between frontend and backend development?
Because of flexibility, many developers consider composition a better technique. Sooner or later, the developer will have to deal with other technologies, programming approaches, and challenges. The level of basic programming knowledge shows how prepared the candidate is to broaden their professional horizons. Here are sample answers to five Node.js interview questions about skills. Refer to the answers provided when reviewing your candidates’ responses. In this example, the readFile() function reads the contents of a file asynchronously.
In this example, fs.readFile() asynchronously reads the content of ‘example.txt’ and calls the provided callback function when the operation is complete. The callback function receives an error (if any) and the file content. This way, the rest of the program can continue executing while the file is being read, enhancing overall performance.
Node.js interview questions about skills with sample answers
Includes classes, methods, and events for creating Node.js http server. Ajax is a client-side technology that updates page content without refreshing the page. Node.js is https://wizardsdev.com/en/vacancy/middle-nodejs-developer-3/ a server-side JavaScript used to develop server software. Further, Node.js is a full-fledged development environment, whereas Ajax just obtains data or runs scripts.
This makes Node.js an ideal choice for microservices and real-time applications. The Node.js asynchronous model is faster and more stable for applications with many concurrent requests than most other languages. Node.js also lets you develop your server and client sides using the same codebase simultaneously.
What is an asynchronous API?
The Buffer class is a global class and can be accessed in an application without having to import the buffer module. It is typically used as pure JavaScript code is not attuned with binary data. Node.js has an EventEmitter class which holds all the objects which can emit events. These objects hold a function called eventEmitter.on() using which multiple functions can be attached to the event emitted by the object. Whenever an object from the EventEmitter class throws an event, all the attached functions to the event are called upon synchronously. The createReadStream process is partially buffered, treating the entire process as a series of events.
Operational errors are not bugs, but create problems with the system like request timeout or hardware failure. If something goes wrong, the programmer has to check the first argument because it is always an error argument. In general, a buffer is a temporary memory mainly used by the stream to hold on to some data until it is consumed. Buffers are used to represent a fixed-size chunk of memory allocated outside of the V8 JavaScript engine. It is like an array of integers, which each represents a byte of data.
What do you understand by Event-driven programming?
The server-side code is vulnerable when a server XSS occurs, and the browser renders this response. To prevent server XSS, you should encode context-sensitive server-side output. Node.js is the technology that enabled the development of the back-end with JavaScript. You can’t work with a JavaScript runtime environment without knowing JavaScript itself. Keep an eye out for candidates who have recent experience using Git and can provide examples of how it has helped them in their projects. For instance, some developers may benefit from the tool’s history-tracking feature or handy code backup option.
It specifies a computer environment like a window console or Unix/Linux shell where you can enter a command, and the computer responds with an output. Yes, Node.js provides a simple TCP based protocol and built-in debugging client. For debugging your JavaScript file, you can use debug argument followed by the js file name you want to debug. Synchronous attachments of the functions are done when the EventEmitter object emits an event.
If there’s an error, it will be passed as the first argument to the callback; otherwise, the data read from the file will be passed as the second argument. As an interviewer, you need to know how to ask the right, practical questions in order to determine if the developer is as skilled as they claim. More importantly, to hire Node.js developers, the more experienced the developer is, the more applied the interview questions should be. The first phase runs the scheduled setTimeout and setInterval callbacks.
Much of her focus is on collaboration, efficiency, and learning. Jamie is a perfectionist to the smallest pixel and has a passion for building custom WordPress themes and React applications. Node.js core modules, as well as most of the community-published ones, follow a pattern whereby the first argument to any callback handler is an optional error object. Node.js is a JavaScript runtime environment based on the V8 engine.