1    /* 
2     * Program to start familiarizing students with arrays and how to manipulate them 
3     */
4    
5    package arrayplay;
6    
7    public class Primes {
8    
9        public static void main(String[] args) {
10           int[] primes = new int[4];
11   
12           primes[0] = 2;
13           primes[1] = 3;
14           primes[2] = 5;
15           primes[3] = 7;
16   
17           System.out.println("length of the primes array " + primes.length);
18           System.out.println("first prime = " + primes[0]);
19           System.out.println("last prime = " + primes[3]);
20           System.out.println("last prime = " + primes[primes.length-1]);
21   
22           System.out.println("\nThe initial array ...");
23           int i =0;
24           while ( i < primes.length) {
25               System.out.println(primes[i]);
26               i = i+1;
27           }
28   
29           int temp = primes[0];
30           primes[0] = primes[primes.length-1];
31           primes[primes.length-1] = temp;
32   
33           System.out.println("\nThe final array");
34           for (int x = 0; x < primes.length; x = x + 1) {
35               System.out.println(primes[x]);
36           }
37   
38       }
39   }
40