1 // Array list program demonstrating the function of a arraylist 2 3 package arraylistplay; 4 5 import java.util.ArrayList; 6 7 public class Primes { 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 the 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 22 System.out.println("\nThe initial list ..."); 23 for( Integer prime : primes ) { 24 System.out.println(prime); 25 } 26 27 int temp = primes.get(0); 28 primes.set(0, primes.get(primes.size()-1)); 29 primes.set(primes.size()-1, temp); 30 31 System.out.println("\nThe final list ..."); 32 for ( Integer prime : primes ) { 33 System.out.println(prime); 34 } 35 } 36 } 37