Suppose list1 is an arraylist and list2 is a linkedlist. both contains 1 million double values. analyze the following code:
a: for (int i = 0; i < list1.size(); i++)
sum += list1.get(i);
b: for (int i = 0; i < list2.size(); i++)
sum += list2.get(i);
a. code fragment a runs faster than code fragment b.
b. code fragment b runs faster than code fragment a.
c. code fragment a runs as fast as code fragment b.

A. Code fragment A runs faster than code fragment B.

Explanation:

I used the following program to test the performance of code fragments A and B:

import java.time.Duration;

import java.time.Instant;

import java.util.ArrayList;

import java.util.LinkedList;

import java.util.List;

import java.util.Random;

public class Test {

   public static void main(String[] args) {

       List<Double> list1 = new ArrayList();

       List<Double> list2 = new LinkedList();

       double sum;

       int N = 1000000;

       Random random = new Random();

       for (int i = 0; i < N; i++) {

           double randomNumber = random.nextDouble();

           list1.add(randomNumber);

           list2.add(randomNumber);

       }

       Instant start1 = Instant.now();

       sum = 0;

       for (int i = 0; i < list1.size(); i++)

           sum += list1.get(i);

       Instant finish1 = Instant.now();

       System.out.println( "Performance of ArrayList: " + Duration.between(start1,finish1).toMillis() + " ms " );

       Instant start2 = Instant.now();

       sum = 0;

       for (int i = 0; i < list2.size(); i++)

           sum += list2.get(i);

       Instant finish2 = Instant.now();

       System.out.println( "Performance of LinkedList: " + Duration.between(start2,finish2).toMillis() + " ms " );

   }

}

And the output was:

Performance of ArrayList: 3 ms

Performance of LinkedList: 5283 ms

As you can see ArrayList code fragment completed much faster than LInkedList code fragment. The reason is that in the case of ArrayList the time complexity of get() method was O(1) whereas in case of LinkedList it required O(N) operations (where N=1000000, more about Big O notation at https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwixx7Ls1cPmAhUnxaYKHS4LBKsQFjAAegQIBBAB&url=https%3A%2F%2Frob-bell.net%2F2009%2F06%2Fa-beginners-guide-to-big-o-notation%2F&usg=AOvVaw1OOzcRQHJ7JsrD7LEYAN_E).

Generally, LinkedList performs faster or equally for data modification and slower for data access.