Is the uniqueness of hashCode guaranteed when inserting an object into a HashMap?

Uniqueness of hashCode when inserting an object into a HashMap is not guaranteed. In Java, hashCode() is an integer value that can be the same for different objects (collisions).

HashMap uses hashCode to determine the bucket, but in case of collisions, it compares objects using equals(). Therefore:

• Several different objects can have the same hashCode.
• For the correct operation of HashMap, it is important to properly override the hashCode() and equals() methods.

If hashCode is not unique, HashMap still correctly stores objects, using chains or trees within the bucket to resolve collisions.