Primes.java
1    /* 
2     * This program forms an array then prints out information about it. 
3     */
4    
5    package arrayplay;
6    
7    public class Primes {
8        public static void main(String[] args) {
9            int[] primes = new int[4];
10   
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           int temp = primes[0];
29           primes[0] = primes[primes.length - 1];
30           primes[primes.length - 1] = temp;
31   
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   }
39