I recently faced a tough question in an interview about how JavaScript's Map maintains the order of insertion. I found it challenging and would really appreciate any insights into this topic. Is there something specific about how the implementation works that I should know?
3 Answers
In interviews like this, I think it's best to take a step back and ask questions yourself. For example, you could say, 'What kind of problems were you solving that led to this question?' It shifts the focus and helps you engage better.
And if they ask about something that seems unreasonable, it's fine to express that. It shows confidence!
If I got that question in an interview, I'd be a bit stumped too! I mean, I'd definitely have to check the spec and maybe even dive into the V8 source code if I wanted to answer thoroughly. But honestly, does it really matter for most developer jobs?
It seems like one of those questions that might be trickier than they realize. Sometimes interviewers just throw in these head-scratchers to see how you think on your feet!
Exactly! Sometimes it's just a test of your approach rather than the actual answer.
JavaScript Maps actually use a combination of a hash table and a linked list to keep track of the insertion order. The linked list allows for maintaining the order as entries are added or removed, which is why you get the order you expect when iterating over a map.
Yeah, and remember that because of the linked list, Maps take up more memory compared to a simple hash table since they must maintain both structures.
Exactly! So, if someone asks how it's implemented in an interview, mentioning this dual structure is a good way to show you've thought deeply about it.
Totally! Interviews are as much about you assessing them as they are about them assessing you.