Express is a great choice for building web applications in Node.js, and its popularity and active community make it a safe and reliable choice for developers of all levels. Libuv is a critical component of Node.js, and it’s what makes it possible to handle I/O operations in a non-blocking and efficient manner. Ajax and Node.js are two different technologies that are used for different purposes.
What is a request object in Express.js?
We use a specific range of challenges and Node.js online tests to find the right candidate for your business. This is one of the top node.js interview questions, as it requires the developer to know both the benefits of single-threading, and what it really is. Middleware in Express.js are functions that have access to the request (req), response (res), and next middleware function in the application’s request-response cycle.
What is the command used to import external libraries?
We have compiled a comprehensive list of common Node.js interview questions that come up often in interviews and the best ways to answer these questions. This will also help you understand the fundamental concepts of Node.js. This thread pool allows Node.js applications to offload the kind of workloads that can’t be executed asynchronously at the level of the operating system (OS). The “createReadStream” process is a partially-buffered process, and that’s the main difference from the “readfile()” process. When executing the “createReadStream” process, Node.js splits a file into chunks. It processes these chunks one by one and sends responses programmer accordingly.
What are some of the flags used in the read/write operations in files?
Node.js will keep executing the code after the functions have been called, without expecting the output prior to the beginning. When running an application, callbacks are entities that have to be handled. Since Node.js supports non-blocking sending, this is a very important feature to have. When working with HTTP connections or in web applications, the synchronous methods may block other requests. Always favor their asynchronous counterparts, especially in web applications.
This is achieved through the use of a sandboxed environment, which can help to prevent malicious code from accessing sensitive data or causing any damage to the system. Secondly, separating your app and server can make it easier to scale your application. By separating the two, you can run multiple instances of your app on different servers, which can help to distribute the load and improve performance.
- The Factory pattern is a creational design pattern that provides an interface for creating objects, allowing subclasses to decide which class to instantiate.
- The event loop in Node Js is a mechanism that enables Node Js to process multiple tasks in parallel.
- Node.js is a platform on which JavaScript code can run on the server-side.
- Once the unit tests are passed, you can write integration tests that test the interaction between different endpoints and components in the API.
- It can speed up application development, improve cloud security, and enhance the reliability of an application’s resources.
- There are a few libraries that developers frequently use with Node.js, so look for a candidate who can name a couple and explain what they are.
- Testing is carried out remotely and once the candidate is finished with their test, the DevSkiller platform gets to work.
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- Syntax errors occur when the code does not conform to the syntax of the language.
- These include try/catch blocks, the error-first callback pattern, and Promises.
- Instead, the supplied callback function is invoked when the read operation finishes.
- The session identifier is typically sent to the client as a cookie, allowing the server to recognize the user across multiple requests.
- You can compare candidates’ knowledge by looking at their easy-to-understand results and then quickly select top candidates for an interview.
It is a modern web technology in which there is a continuous connection between the user’s browser (client) and the server. In this type of communication, between the web server and the web browser, both of them can send messages to each other at any point in time. Traditionally on the web, we had a request/response format where a user sends an HTTP request and the server responds to that. This is still applicable in most cases, especially those using RESTful API.
RESTful API is an architectural style for designing networked applications based on the principles of representational state transfer (REST). Clustering in Node.js involves spawning multiple instances of the Node.js process to utilize multiple CPU cores effectively. If it’s /profile, the server will respond with a « Welcome! » message; otherwise, it will respond with « Hello, World! ». During the Travis CI build, you can run npm test to execute Mocha tests as per the package.json configuration. Traditionally, concurrency can be achieved in languages that support multithreading (e.g., Java). However, managing and coordinating multiple threads can be challenging and is a common source of bugs.
intermediate Node.js interview questions to ask candidates
It assists in identifying the current environment of your application, whether it’s for development, production, or testing purposes. There are other parameters, such as the options used to set the input as an integer or an object. Make sure to answer it to the junior node js developer best of your abilities, and do not bloat, but give your honest experiences and explain how you’ve used Node.js before.
What are some commonly used Node.js development tools?
Node Js enables web developers to create web applications quickly and easily. It provides an event-driven, non-blocking I/O model for web applications. Additionally, Node Js makes it easier to manage web application resources because of its asynchronous programming features.