Picking a random element from a set

Question

How do I pick a random element from a set? I'm particularly interested in picking a random element from a HashSet or a LinkedHashSet, in Java. Solutions for other languages are also welcome.

Answer 1

Try:

int size = myHashSet.size();

int item = new Random().nextInt(size); // In real life, the Random object should be rather more shared than this

int i = 0;

for(Object obj : myhashSet)

{

    if (i == item)

        return obj;

    i++;

}