1    ///This program will look at what an array is, what an index is, and what elements are.
2    
3    package arrayplay;
4    
5    public class Primes {
6        public static void main(String[] args){
7            int[] primes = new int[4];
8    
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   
27           int temp = primes[0];
28           primes[0] = primes[primes.length-1];
29           primes[primes.length-1] = temp;
30   
31           System.out.println("\nThe final array ...");
32           for (int x = 0; x< primes.length; x = x + 1){
33               System.out.println(primes[x]);
34           }
35   
36       }
37   }
38