In this section we are discussing HashSet with example code that shows the methods to add, remove and iterate the values of collection. A HashSet is a collection set that neither allows duplicate elements nor order or position its elements.
Description of program:
following code segment we are performing various operations on HashSet
We have explained the steps to add, remove, and test the
elements of the collection. Keys are used to put and get values.
We can also
execute this code on a
Vector by changing the HashSet declaration and
constructor to a Vector as it supports the collection interface.
To insert an element in the HashSet collection add() method is used. The size() method helps you in getting the size of the collection. If you want to delete any element, use the remove() method which takes index as parameter. In order to remove all data from the HashSet use clear() method. When the HashSet is empty, our program checks for it and displays a message "Collection is empty". If the collection is not empty then program displays the size of HashSet.
Here is the code of program:
Output of this program:
Collection data: Blue White Green Yellow
Collection size: 4
After removing [White]
Now collection data: Blue Green Yellow
Collection size: 3
Collection is empty