15.3.2.1. HashSet

Try these first

1. 1.

   What is the primary purpose of a HashSet in Java?

   Hint

   Think about how sets work in mathematics.

2. 2.

   Name one method used to add an element to a HashSet.

   Hint

   Consider the name of the method that suggests adding items.

3. 3.

   What is the primary characteristic of a HashSet?

   • Maintains order
   • Allows duplicates
   • Stores unique elements

   Hint

   Think about how a typical set behaves.

4. 4.

   True or False: The order of elements in a HashSet is guaranteed.

   • True
   • False

   Hint

   Recall what unordered means.

5. 5.

   You are tasked with creating a contact manager that should not allow duplicate contacts. How would you utilize HashSet in your solution? Write a sample code snippet demonstrating how you would add and check contact names.

   Hint

   Consider how you would check for duplicates before adding.

6. 6.

   Explain how you'd handle equality in HashSet's elements to prevent collisions effectively. What key methods must be overridden?

   Hint

   Think about the rules for comparison in programming.