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