Domanda di colloquio di EPAM Systems

What if we insert with key null to a HashMap?

Risposte di colloquio

Anonimo

4 mag 2019

Didn't know, however, it's a very edge case, you can insert and the hashcode will be 0, so it's identifying the '0' bucket.

Anonimo

1 set 2020

HashMap allows null as both key and value, as well. So you can associate a value to null key. However, TreeMap throws a NullPointerException if you try to put a key with null value.