Primes.java
1    /* 
2     *program features an array of single digit primes. 
3     */
4    
5        package arrayplay;
6    
7        public class Primes {
8                public static void main(String [] args){
9    
10           int[] primes = new int[4];
11           primes[0] = 2;
12           primes[1] = 3;
13           primes[2] = 5;
14           primes[3] = 7;
15   
16           System.out.println("length of primes array = " + primes.length);
17           System.out.println("first prime = " + primes[0]);
18           System.out.println("last prime = " + primes[3]);
19           System.out.println("last prime = " + primes[primes.length-1]);
20   
21           System.out.println("\nThe initial array ...");
22           int i = 0;
23           while(i<primes.length){
24               System.out.println(primes[i]);
25               i = i+1;
26   
27           }
28   
29               int temp = primes[0];
30               primes[0] = primes[primes.length-1];
31               primes[primes.length-1]= temp;
32               System.out.println("\nThe final array ...");
33               for( int x = 0; x < primes.length; x = x + 1){
34                    System.out.println(primes[x]);
35               }
36        }
37   }
38