1 package arraylistplay; 2 3 import java.util.ArrayList; 4 5 public class Primes { 6 7 8 public static void main(String[] args) { 9 10 ArrayList<Integer> primes = new ArrayList<>(); 11 12 primes.add(2); 13 primes.add(3); 14 primes.add(5); 15 primes.add(7); 16 17 System.out.println("size of primes list = " + primes.size()); 18 System.out.println("first prime = " + primes.get(0)); 19 System.out.println("last prime = " + primes.get(3)); 20 System.out.println("last prime = " + primes.get(primes.size() - 1)); 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 37 38 } 39