1    package arraylistplay;
2    
3    /* 
4    * This program tests the functionality of ArrayLists in Java. 
5     */
6    
7    import java.util.ArrayList;
8    
9    public class Primes {
10       public static void main(String[] args)
11       {
12           ArrayList<Integer> primes = new ArrayList<>();
13   
14           primes.add(2);
15           primes.add(3);
16           primes.add(5);
17           primes.add(7);
18   
19           System.out.println("size of primes list = " + primes.size());
20           System.out.println("first prime = " + primes.get(0));
21           System.out.println("last prime = " + primes.get(3));
22           System.out.println("last prime = " + primes.get(primes.size()-1));
23   
24           System.out.println("\nThe initial list...");
25           for(Integer prime: primes)
26           {
27               System.out.println(prime);
28           }
29   
30           int temp = primes.get(0);
31           primes.set(0, primes.get(primes.size() - 1));
32           primes.set(primes.size()-1, temp);
33   
34           System.out.println("\nThe final list...");
35           for(Integer prime:primes)
36           {
37               System.out.println(prime);
38           }
39       }
40   }
41