1    //dealing with array lists in a simple way
2    
3    package arraylistplay;
4    
5    import java.util.ArrayList;
6    
7    public class Primes {
8        public static void main(String[] args){
9            ArrayList<Integer> primes = new ArrayList<>();
10   
11           primes.add(2);
12           primes.add(3);
13           primes.add(5);
14           primes.add(7);
15   
16           System.out.println("size of primes list = " + primes.size());
17           System.out.println("first prime = " + primes.get(0));
18           System.out.println("last prime = " + primes.get(3));
19           System.out.println("last prime = " + primes.get(primes.size()-1));
20   
21           System.out.println("\nThe initial list ...");
22           for (Integer prime: primes ){
23               System.out.println(prime);
24           }
25           int temp = primes.get(0);
26           primes.set(0, primes.get(primes.size()-1));
27           primes.set(primes.size()-1,temp);
28   
29           System.out.println("\nThe final list ...");
30           for ( Integer prime : primes) {
31               System.out.println(prime);
32           }
33       }
34   }
35