1 package arraylistplay; 2 3 import java.util.ArrayList; 4 5 public class Primes { 6 7 public static void main (String[] args) { 8 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 System.out.println("\nThe final list ..."); 30 for (Integer prime : primes ) { 31 System.out.println(prime); 32 } 33 } 34 } 35