COP 3530
Section U03
Spring 2017



                       The Collection Interface
                       ========================




 Here is an example of how we can use the Collection interface.




// test collection
import java.util.*;

public class Fall14TestCollection 
{

    public static void main(String[] args)
    {
        System.out.println("Test the Collection Interface");
        System.out.println("=============================\n\n");
        
        // test the printing
        System.out.println("We first test the printing.");
        System.out.println("We form an array list with the names Bill, Mark, Ana.");
        ArrayList<String> friends = new ArrayList();
        friends.add("Bill");
        friends.add("Mark");
        friends.add("Ana");
        friends.add("Gandpa");

        System.out.println("\nThe list of friends:");
        printCollection(friends);

        System.out.println("\nWe form a set of the integers 7, 3, 5.");
        TreeSet<Integer> integers = new TreeSet();
        integers.add(7);
        integers.add(3);
        integers.add(5);

        System.out.println("\nThe tree of integers:");
        printCollection(integers);
        
        // form a linked list of names
        System.out.println("\nWe form a linked list of new friends.");
        LinkedList<String> newFriends = new LinkedList<>();
        newFriends.add("Tornado");
        newFriends.addFirst("Shrek");
        newFriends.add("Cortadito");
        
        System.out.println("\nWe print the new friends.");
        printCollection(newFriends);
        System.out.println("\nWe add the new friends to the array of friends.");
        friends.addAll(newFriends);
        System.out.println("\nWe print the updated friends array list.");
        printCollection(friends);
        

     }

     // print a collection using an iterator
     public static <T> void printCollection( Collection<T> c)
     {
         Iterator<T> itr = c.iterator();
         while (itr.hasNext())
         {
             System.out.println(itr.next());
         }
     }

    
}


The output:

run:
Test the Collection Interface
=============================


We first test the printing.
We form an array list with the names Bill, Mark, Ana.

The list of friends:
Bill
Mark
Ana
Gandpa

We form a set of the integers 7, 3, 5.

The tree of integers:
3
5
7

We form a linked list of new friends.

We print the new friends.
Shrek
Tornado
Cortadito

We add the new friends to the array of friends.

We print the updated friends array list.
Bill
Mark
Ana
Gandpa
Shrek
Tornado
Cortadito
BUILD SUCCESSFUL (total time: 0 seconds)