What are the differences between hash maps and arrays?

What are the differences between hash maps and arrays?

Hash maps and arrays are both data structures, but they serve different purposes. Arrays are ordered collections of elements, while hash maps store key-value pairs for fast lookups.

Can you explain how the performance differs between them?

Sure! Arrays have O(1) time complexity for accessing elements by index, while hash maps have O(1) average time complexity for lookups, but O(n) in the worst case due to collisions.

When should I use a hash map instead of an array?

Use a hash map when you need fast lookups, insertions, or deletions based on keys. Arrays are better for ordered data and when you need to access elements by their index.

Are there any downsides to using hash maps?

Yes, hash maps can consume more memory than arrays due to their underlying structure and may have slower performance in cases of high collision rates.