Give me a practical use-case of Multi-set

Question

I would like to know a few practical use-cases (if they are not related/tied to any programming language it will be better).I can associate Sets, Lists and Maps to practical

Answer 1

A multiset is useful in many situations in which you'd otherwise have a Map. Here are three examples.

Suppose you have a class Foo with an accessor getType(), and you want to know, for a collection of Foo instances, how many have each type.

Similarly, a system could perform various actions, and you could use a Multiset to keep track of how many times each action occurred.

Finally, to determine whether two collections contain the same elements, ignoring order but paying attention to how often instances are repeated, simply call

HashMultiset.create(collection1).equals(HashMultiset.create(collection2))