where are the best places to use hash maps

Question

what are the applications of hash maps

Answer 1

Hashmaps are good when you're trying to keep a "dictionary" of items.

Let's say, for example, you have a phonebook. That phonebook has a list of names and a list of phone numbers, and order isn't necessary. You can use a hashmap to store the names as keys and allocate each name to a phone number.

This isn't as easy with other types of collections, like lists that store a value with an index in an order.

Sure, you can decide to use things like parallel arrays or parallel lists, but why bother? Hashmaps are easier to read and are already built in for you to use for a key:value pair.

If you do need to retain order, you can also use subclasses like linkedHashMap (at least, in Java you can - not sure about other languages).

Hope this helps.

Answer 2

I use pycharm.