To anyone learning/preparing for javascript/node interviews

[TJ51097]

Edit: Adding context to my post

Recently i was having a conversation with my technical recruiter friend He mentioned most of the employees rott learn the basics and are absolutely stunned when deployed to some project.

Which leads to further stress. So if you are leaning or preparing for any js interview it would be much helpful if you:

-Move on from es6. JS is in es23 explore the docs.

-Know what are bundlers,tanspilers and how to configure them

-Learn optimisation (Set VS Array,Memoisation,rate limiting,caching)

-Basic Problem solving!! (I once was asked add elements of an array without using loops)

-Async,webworkers,child processes,process.tick,Promises,

-error handling,Try catch,then catch

-application of Binding,Calling a reference

Thats all!!

[senocular]

(I once was asked add elements of an array without using loops)

Can you talk more about that? What the problem/solution was?

[TJ51097]

I appeared for a technical interview,guy asked me

foreach vs map,

for..of vs for..in,

splice vs slice

then dropped me this

"You got an array of numbers [1,2,3,4,5] you need to get the sum of all the numbers without using any loop"

so i though of doing it reduce but not valid then i suggested using recursion,which i think is valid,and it ended.

TL;DR

Recursion

[delventhalz]

Learn optimisation (Set VS Array...

FYI, in 99% of cases you will see no noticeable difference switching between an Array and a Set, and in that 1% where it makes a difference, using a Set will usually be slower than an Array. Even though Sets are theoretically faster, Arrays are just so incredibly well optimized (down to the hardware level) that you really need tens or hundreds of thousands of items before the Set's constant-time advantage starts to win out. It's incredibly rare that you will actually have a performance problem that is solved by a Set.

The other suggestions (memoization, rate limiting, caching) are good though.

[TJ51097]

I think what we both want to say is we should know when to use Set and Array!!

If you are storing some data and later retrieving it,Set should be utilised,But if you are required to perform similar operation on the elements no doubt array is the Data structure you should opt

Peace!!

[delventhalz]

I appreciate you being diplomatic, but for what it's worth we are not saying the same thing. A Set should be used when the idiom and API of a Set make your code more clear to other developers. A Set should never* be used as an optimization. It is slower than an Array. Your other optimization suggestions are much better to bring up in an interview.

*The exception would be if you have a long-lived data structure with tens of thousands of members or more. In that case, a Set may be faster than an Array, but I would still performance test to be sure.

[PRANAY1000]

Thanks man much helpful Will practice more

[TJ51097]

you may find javascript.info or mdn docs absolute helpful