By Govind Geek What are the most advanced Node.js Interview questions, and the answers?
Node.js is a well-known server-side application used by a variety of diverse organizations. If you’re planning to change careers or are scheduled for an interview It’s always a good idea to plan and practice the skills you need to present yourself.
We’ve created an exhaustive list of common interview questions asked in Node.js interviews, as well as the most effective ways to address them.
This list of the top ten advanced Node.js questions for interviews will assist you in preparing for the interview increasing your confidence, and boosting your odds of getting the Backend Developer job of your goals!
Make a high-end Node.js resume and be connected to Node.js positions as a developer around the world without jeopardizing your privacy of.
Advanced Node.js Interview Questions and Answers
1. What is REPL in Node.js?
Read-Eval-Print Loop (REPL) can be described as an interactive Shell that runs Node.js and is a representation of a computing environment. It’s akin to a Windows console as well as a Unix/Linux Shell where you type in a command. Following that, the system will respond by displaying an output.
Read – Reads user’s input and parses it into the JavaScript database structure and then stores the data in memory.
Eval – Retrieves the data structure and assesses the structure of data.
Print – Prints the results.
Loop – Loops this operation until a user presses ctrl-c two times.
2. How do I use the Control flow feature that is used in Node.js?
Like many languages, Node.js/JavaScript comes with a standard set of control flow patterns that operate just similarly to other languages.
Control flow functions are a simple program that is executed between functions that are synchronous and are arranged to:
- determine the execution order
- collect data,
- limit concurrency
- The next step is the one to be called in the program.
3. What exactly is callback hell? How do you stay clear of callback hell?
Hellish callbacks within Node.js Also called the pyramid of death, is when we have complicated callbacks that are nested. In this case, each callback uses the arguments gathered from previous callbacks. This type of callback structure reduces the code’s readability and also less maintainability.
With Promises’ help, we can end the callback nightmare. Promises in Javascript can be used to run asynchronous tasks in Node.js. It lets us return the value of an Asynchronous function, for example, the synchronous function.
4. What is the Reactor Pattern?
It is the Reactor Model that helps to stop I/O operations from getting blocked. This model has an associated handler for every I/O operation.
If I/O requests are generated they are then transmitted to a multiplexer, which manages concurrency, and then aggregates the requests into events and then queues them so that they don’t block I/O. I/O mode.
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5. What is the reason why Google utilize the V8 engine in Node.js?
The V8 engine is the JavaScript engine that runs Google Chrome. It’s the engine that takes JavaScript and then executes it when browsing on Chrome.
V8’s engine is open source and built by hand in C++ (Google Chrome utilizes the engine). In addition, in contrast to other engines, it is employed in the renowned Node.js runtime.
Instead of utilizing an interpreter, V8 converts JavaScript code into machine code that is more efficient to boost performance. The engine converts JavaScript code into machine code when it executes with the JIT (Just In Time) compiler, similar to what many modern JavaScript engines such as SpiderMonkey and Rhino (Mozilla) use.
6. What is the meaning of middleware within Node.js?
Middleware is a program that takes in request and response objects, much like your route handlers.
Some of the jobs middleware performs are:
- Perform any code
- Request or replacement for update or replacement and response objects
- Complete the cycle of request-response
- The next middleware to be called within the stack
7. What’s the function of NODE_ENV?
NODE_ENV is a system-wide environmental variable which Node exposes to scripts running.
This kind of variable can be changed according to the current environment that the program runs on.
NODE_ENV functions as a flag that tells you if the server is operating in production or development mode. The express framework examines the value of the flag at the time of execution and adjusts the value based on the specific environment.
8. What are the different characteristics of timing in Node.js?
Timer modules within Node.js comprise functions that aid in controlling the timeframe of code execution. It comprises setsTimeout() setImmediate() and setInterval() methods.
- setTimeout(): The setTimeout() method is used to plan the execution of code following a predetermined amount of milliseconds.
- setImmediate() The setImmediate() procedure is utilized to run code at the end of the current loop.
- setInterval(): The setInterval() method is used to invoke an application at specific intervals (in milliseconds). The function is executed only one time after the set period.
9. What is WASI?
WASI is an open system interface that can be used with WebAssembly.
WASI has been standardized as a subgroup of WebAssembly CG.
Every WASI instance represents a unique sandbox environment. Every WASI instance has to specify its command-line parameters and environment variables and the structure of the sandbox directory to protect itself.
