You can have a Map as key but as you pointed out since a Map is (typically) mutable the key changes.
Read moreAre keys in a map unique?
The keys are unique in all maps . The difference between the various maps implementations concern the possibility of null keys, the order of iteration and concurrency issues.
Read moreAre keys in a map unique?
The keys are unique in all maps . The difference between the various maps implementations concern the possibility of null keys, the order of iteration and concurrency issues.
Read moreWhy is TreeMap slower than HashMap?
Conclusions. HashMap is a general purpose Map implementation. It provides a performance of O(1) , while TreeMap provides a performance of O(log(n)) to add, search, and remove items . Hence, HashMap is usually faster.
Read moreCan we convert HashMap to TreeMap?
Get the HashMap to be converted. Create a new TreeMap . Pass the hashMap to putAll() method of treeMap . Return the formed TreeMap .1 Eki 2021
Read moreWhich is better HashMap or TreeMap?
HashMap is faster than TreeMap because it provides constant-time performance that is O(1) for the basic operations like get() and put(). TreeMap is slow in comparison to HashMap because it provides the performance of O(log(n)) for most operations like add(), remove() and contains().
Read moreWhat is the difference between a HashMap and a TreeMap?
HashMap allows storing at most one null key and many null values. However, TreeMap doesn’t allow a null key but may contain many null values . If we’re using a TreeMap with a user-defined Comparator, then it depends on the implementation of the compare() method how null values get handled.9 Nis 2020
Read more