1    /* 
2    * A program including an array of prime numbers to explore arrays 
3     */
4    package arrayplay;
5    
6    public class Primes {
7        public static void main(String[] args){
8            int[] primes = new int[4];
9            primes[0] = 2;
10           primes[1] = 3;
11           primes[2] = 5;
12           primes[3] = 7;
13   
14           System.out.println("length of primes array = " + primes.length);
15           System.out.println("first prime = " + primes[0]);
16           System.out.println("last prime = " + primes[3]);
17           System.out.println("last prime = " + primes[primes.length-1]);
18   
19           System.out.println("\nThe initial array ...");
20           int i = 0;
21           while(i < primes.length){
22               System.out.println(primes[i]);
23               i = i +1;
24           }
25   
26           int temp = primes[0];
27           primes[0] = primes[primes.length-1];
28           primes[primes.length-1] = temp;
29   
30           System.out.println("\nThe final array ...");
31           for (int x = 0; x < primes.length; x = x+1){
32               System.out.println(primes[x]);
33           }
34   
35       }
36   }
37