15.1. The Java Collections Framework Overview

Try these first

1. 1.

   What is a Collection in Java?

   Hint

   Think of it as a container.

2. 2.

   Name two core interfaces of the Java Collections Framework.

   Hint

   Consider common data structures.

3. 3.

   What does a Collection in Java do?

   • Stores single items only
   • Groups multiple elements into a single unit
   • Only allows unique items

   Hint

   Think of it like a box containing many items.

4. 4.

   True or False: A List cannot contain duplicate elements.

   • True
   • False

   Hint

   Consider an example where you can have the same object multiple times.

5. 5.

   Design a program that demonstrates the use of List, Set, and Map. Create a List to hold your favorite movies, a Set for unique genres, and a Map where the keys are movie titles and values are their release years.

   Hint

   Use ArrayList for movies, HashSet for genres, and HashMap for storing titles and years.

6. 6.

   Explain the advantages of using the Set interface over List when handling a collection of user IDs in an application.

   Hint

   Consider what happens if a user enters their ID multiple times.