is collections.sort method only used for List type of collections?

Question

friends, I am new to Java-Collection. I want to ask does Collections.sort() method only used for/by collections which are List type. I was unable t

Answer 1

Collections.sort method expects a collection that implements a List interface. This makes sense, because lists have a defined sequence. In other words, your program has complete control of the order of what goes in the list.

Unlike lists, sets are either unordered, or specify their own, specific ordering. That is why trying to sort a Set does not make sense: it is the set, not your program, that defines the ordering of the items in the set collection. Your program can provide the logic to customize that ordering, but you cannot take an existing set, and force a different order on its items from the outside.

If you would like to get all items of a set collection in a sorted order, copy your set into an array list, and sort the results.