How do hash tables work?

Can you explain how hash tables work?

Sure! A hash table is a data structure that stores key-value pairs. It uses a hash function to compute an index into an array of buckets or slots, from which the desired value can be found.

What is a hash function?

A hash function takes an input (or 'key') and returns a fixed-size string of bytes. The output is typically a number that corresponds to an index in the hash table.

What happens if two keys hash to the same index?

That's called a collision. Hash tables handle collisions using methods like chaining (linking entries at the same index) or open addressing (finding another open slot).

Are hash tables efficient?

Yes, hash tables offer average-case constant time complexity for lookups, insertions, and deletions, making them very efficient.