When should I use a hash map?

When should I use a hash map instead of a list?

You should use a hash map when you need fast lookups, insertions, and deletions, as it offers average O(1) time complexity.

Can you give me an example of when a hash map is more efficient?

Sure! If you're counting the frequency of words in a text, a hash map allows you to store each word as a key and its count as the value, making it very efficient.

Are there any downsides to using hash maps?

Yes, hash maps can consume more memory than lists, and they can have performance issues if many keys hash to the same value, causing collisions.

What are some common use cases for hash maps?

Common use cases include caching, implementing associative arrays, and counting occurrences of items.