Java – get random numbers from ArrayList?

ArrayList<Integer>  lista = new ArrayList<Integer>();

ArrayList<Integer>  lista = new ArrayList<Integer>();
lista.add(159);
lista.add(170);
lista.add(256);

For example, I get these three numbers in my ArrayList, and I want to get one of them at random How is that possible?

Solution

One way is to use the random class:

ArrayList<Integer>  lista = new ArrayList<Integer>();
lista.add(159);
lista.add(170);
lista.add(256);

Random r = new Random();
System.out.println(lista.get(r.nextInt(lista.size())));

Or use shuffle:

ArrayList<Integer>  lista = new ArrayList<Integer>();
lista.add(159);
lista.add(170);
lista.add(256);

Collections.shuffle(lista);
System.out.println(lista.get(0));