Question-41. What are some of the flags used in the read/write operations in files?
Question-42. How do you open a file in Node.js?
Question-43. What is callback hell?
- Callback hell, also known as the pyramid of doom, is the result of intensively nested, unreadable, and unmanageable callbacks, which in turn makes the code harder to read and debug
- improper implementation of the asynchronous logic causes callback hell
Question-44. What is a reactor pattern in Node.js?
Answer- A reactor pattern is a concept of non-blocking I/O operations. This pattern provides a handler that is associated with each I/O operation. As soon as an I/O request is generated, it is then submitted to a demultiplexer
Question-45. What is a test pyramid in Node.js?
Question-46. For Node.js, why does Google use the V8 engine?
Answer- The V8 engine, developed by Google, is open-source and written in C++. Google Chrome makes use of this engine. V8, unlike the other engines, is also utilized for the popular Node.js runtime. V8 was initially intended to improve the speed of JavaScript execution within web browsers. Instead of employing an interpreter, V8 converts JavaScript code into more efficient machine code to increase performance. It turns JavaScript code into machine code during execution by utilizing a JIT (Just-In-Time) compiler, as do many current JavaScript engines such as SpiderMonkey or Rhino (Mozilla).
Question-47. Describe Node.js exit codes.
Question-48. Explain the concept of middleware in Node.js.
Answer- Middleware is a function that receives the request and response objects. Most tasks that the middleware functions perform are:
- Execute any code
- Update or modify the request and the response objects
- Finish the request-response cycle
- Invoke the next middleware in the stack
Question-49. What are the different types of HTTP requests?
Answer- HTTP defines a set of request methods used to perform desired actions. The request methods include:
GET: Used to retrieve the data
POST: Generally used to make a change in state or reactions on the server
HEAD: Similar to the GET method, but asks for the response without the response body
DELETE: Used to delete the predetermined resource
Question-50. How would you connect a MongoDB database to Node.js?
Answer- To create a database in MongoDB:
- Start by creating a MongoClient object
- Specify a connection URL with the correct IP address and the name of the database you want to create
