1    /* 
2     * Reasonable lead comment... 
3     * (primes main method) 
4     */
5    
6    package arraylistplay;
7    
8    import java.util.ArrayList;
9    
10   public class Primes {
11   
12       public static void main(String[] args) {
13   
14           ArrayList<Integer> primes = new ArrayList<>();
15   
16           primes.add(2);
17           primes.add(3);
18           primes.add(5);
19           primes.add(7);
20   
21           System.out.println("size of primes list = " + primes.size());
22           System.out.println("first prime = " + primes.get(0));
23           System.out.println("last prime = " + primes.get(3));
24           System.out.println("last prime = " + primes.get(primes.size()-1));
25   
26           System.out.println("\nThe initial list ...");
27           for ( Integer prime : primes ) {
28               System.out.println(prime);
29           }
30   
31           int temp = primes.get(0);
32           primes.set(0, primes.get(primes.size()-1));
33           primes.set(primes.size()-1,temp);
34   
35           System.out.println("\nThe final list ...");
36           for ( Integer prime : primes ) {
37               System.out.println(prime);
38           }
39   
40       }
41   
42   }
43