Set is an unordered collection, it doesn't maintain any order. There are few implementations of Set which maintains the order such as LinkedHashSet (It maintains the elements in insertion order). 2) List allows duplicates while Set doesn't allow duplicate elements. ... 3) List implementations: ArrayList, LinkedList etc.

Why is set unordered?

Set is an ordered sequence of unique keys whereas unordered_set is a set in which key can be stored in any order, so unordered. Set is implemented as a balanced tree structure that is why it is possible to maintain order between the elements (by specific tree traversal).

What is unordered set in Java?

The set interface is present in java. util package and extends the Collection interface is an unordered collection of objects in which duplicate values cannot be stored. It is an interface that implements the mathematical set.