1 package arraylistplay; 2 3 import java.util.ArrayList; 4 5 //A program to introduce the use of ArrayLists 6 7 public class Primes { 8 public static void main(String[] args){ 9 ArrayList<Integer> primes = new ArrayList<>(); 10 11 primes.add(2); 12 primes.add(3); 13 primes.add(5); 14 primes.add(7); 15 16 System.out.println("size of primes list: " + primes.size()); 17 System.out.println("first prime: " + primes.get(0)); 18 System.out.println("last prime: " + primes.get(3)); 19 System.out.println("last prime: " + primes.get(primes.size()-1)); 20 21 System.out.println("\nThe initial list..."); 22 for (Integer prime : primes){ 23 System.out.println(prime); 24 } 25 26 int temp = primes.get(0); 27 primes.set(0, primes.get(primes.size()-1)); 28 primes.set(primes.size()-1, temp); 29 30 System.out.println("\nThe final list"); 31 for (Integer prime : primes){ 32 System.out.println(prime); 33 } 34 } 35 } 36