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