The video tutorial covers three types of sets in Java: HashSet, LinkedHashSet, and TreeSet. It explains how HashSet stores elements without any order, LinkedHashSet maintains the insertion order, and TreeSet keeps elements sorted. The tutorial includes examples of adding and printing elements in each set type, highlighting their unique properties. An exercise is provided to find unique characters in a list using these sets, emphasizing the choice of collection based on the desired order of elements.

What is a key characteristic of a HashSet in Java?

• It stores elements in a sorted order.

• It maintains the order of insertion.

• It does not maintain any specific order.

• It allows duplicate elements.

Which of the following is true about a LinkedHashSet?

• It sorts elements in ascending order.

• It maintains the order of insertion.

• It is slower than a HashSet.

• It allows duplicate elements.

What happens when you try to add a duplicate element to a LinkedHashSet?

• The duplicate element is added.

• The set is cleared.

• An error is thrown.

• The duplicate element is ignored.

How does a TreeSet store its elements?

• In reverse order.

• In a random order.

• In the order of insertion.

• In a sorted order.

If you need unique characters in sorted order, which Java collection would you use?

• LinkedHashSet

• ArrayList

• HashSet

• TreeSet