41. In the context of Node.js, differentiate between operational and programmer errors.
Answer : Operational errors are not real errors. They are system errors, for example “request timeout” or “hardware error”. Programmer errors are actual bugs in the code.
42. What are the two arguments that async.queue takes?
Answer : The two arguments that async.queue takes
43. What is an event loop in Node.js ?
Answer : To process and handle external events and to convert them into callback invocations an event loop is used. So, at I/O calls, node.js can switch from one request to another .
44. Mention the steps by which you can async in Node.js?
Answer : By following steps you can async Node.js
a)First class functions
45. How to solve “Process out of Memory Exception” in Node.js ?
Answer : To solve the process out of memory exception in Node.js we need to increase the max-old-space-size. By default the max size of max-old-space-size is 512 mb which you can increase by the command node –max-old-space-size=1024 file.js.
46. How many types of API functions are available in Node.js?
Answer : There are two types of API functions in Node.js:
Asynchronous, Non-blocking functions
Synchronous, Blocking functions
47. Define “event-driven programming.
Answer : It is essentially a programming paradigm where the program flow is characterized by events such as messages from other programs.
48. List some of the big advantages of using Node.js.
Answer : Ability to build scalable programs
49. What are the pros and cons of Node.js?
b)Crawlers receive a full-rendered HTML response, which is far more SEO friendly rather than a single page application or a websockets app run on top of Node.js.
a)Any intensive CPU computation will block node.js responsiveness, so a threaded platform is a better approach.
b)Using relational database with Node.js is considered less favourable
50. How Node.js overcomes the problem of blocking of I/O operations?
Answer : Node.js solves this problem by putting the event based model at its core, using an event loop instead of threads.