Question

Write a class that can make comparisons between the efficiency of the common methods from the List interface in the ArrayList and LinkedList classes such as add, get, and remove. Use the polymorphic-variable technique described above to write the class so that it only knows it is performing its tests on objects of the interface type List rather than on the concrete types ArrayList and LinkedList. Use large lists of objects for the tests, to make the results significant. You can use the currentTimeMillis method of theSystem class for getting hold of the start and finish time of your test methods.

Answer 1

Answer:

Check the explanation

Explanation:

CODE TO COPY:

File: ArrayListVsLinkedlIst.java

// ArrayListVsLinkedlIst class implementation

import java.util.*;

public class ArrayListVsLinkedlIst

{

  public static void main(String[] args)

  {

      // create a constant for the size of each list

      final int SIZE = 300000;

      // create the required objects

      List<Integer> aList = new ArrayList<Integer>();

      List<Integer> lList = new LinkedList<Integer>();

      // declare the required variables

      long start, end;

      int i;

      // comparison between the efficiency of the add() method

      // from the ArrayList and LinkedList classes

      System.out.println("Time in milliseconds to add " + SIZE

              + " numbers to each list ...");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          aList.add(i);

      }

      end = System.currentTimeMillis();

      System.out.println("ArrayList: " + (end - start) + " ms");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          lList.add(i);

      }

      end = System.currentTimeMillis();

      System.out.println("LinkedList: " + (end - start) + " ms");

      // comparison between the efficiency of the get() method

      // from the ArrayList and LinkedList classes

      System.out.println("\nTime in milliseconds to get " + SIZE

              + " numbers from each list ...");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          aList.get(i);

      }

      end = System.currentTimeMillis();

      System.out.println("ArrayList: " + (end - start) + " ms");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          lList.get(i);

      }

      end = System.currentTimeMillis();

      System.out.println("LinkedList: " + (end - start) + " ms");

      // comparison between the efficiency of the remove() method

      // from the ArrayList and LinkedList classes

      System.out.println("\nTime in milliseconds to remove " + SIZE

              + " numbers from each list ...");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          aList.remove(0);

      }

      end = System.currentTimeMillis();

      System.out.println("ArrayList: " + (end - start) + " ms");

      start = System.currentTimeMillis();

      for (i = 0; i < SIZE; i++)

      {

          lList.remove(0);          

      }

      end = System.currentTimeMillis();

      System.out.println("LinkedList: " + (end - start) + " ms");

  }

} // end of ArrayListVsLinkedlIst class

The screenshot and output images can be seen below.