> 原文:[https://www . geesforgeks . org/how-copy-or-append-hashset-to-other-hashset-in-Java/](https://www.geeksforgeeks.org/how-to-copy-or-append-hashset-to-another ...

A HashSet is a collection class in Java that implements the Set interface. It stores unique elements and does not allow duplicates. Internally, it uses a hash table to store the elements, which ...