Does adding a duplicate value to a HashSet/HashMap replace the previous value

Question

Please consider the below piece of code:

HashSet hs = new HashSet();
hs.add("hi"); -- (1)
hs.add("hi"); -- (2)

hs.size() will give 1 as HashSet doesn't allow duplicates so only one element will be stored.

I want to know if we add the duplicate element, then does it replace the previous element or it simply doesn't add it?

Also, what will happen usingHashMap for the same case?

Answer 1

In the case of HashMap, it replaces the old value with the new one.

In the case of HashSet, the item isn't inserted.