15.3.2. Implementations

Try these first

1. 1.

   What is a HashSet in Java?

   Hint

   Think about its fast retrieval capabilities.

2. 2.

   Which implementation retains insertion order?

   Hint

   It includes 'linked' in its name!

3. 3.

   Which of the following allows duplicate elements?

   • HashSet
   • Set interface
   • TreeSet

   Hint

   Remember that all sets are distinct by their nature.

4. 4.

   True or False: LinkedHashSet also does not allow duplicates.

   • True
   • False

   Hint

   Think about what makes a Set a Set.

5. 5.

   Create a class that maintains a list of unique email addresses using a HashSet. Also, explain potential issues if duplicates are added.

   Hint

   Consider the importance of unique identifiers in email systems.

6. 6.

   Design an application that uses TreeSet for storing student grades, ensuring they are sorted. Discuss the trade-offs of performance.

   Hint

   Think about how sorting enhances the usability of grade listings.