Question

How do you shuffle elements in a Map, I am looking for something similar to the Collections.shuffle method.

Answer 1

A Map is not really ordered like a List, which means you cannot access Map items by index. Hence shuffling doesn’t make sense in general. But what you could do is this (I omitted generics for the example):

Map map = new HashMap();

// [...] fill the map

List keys = new ArrayList(map.keySet());
Collections.shuffle(keys);
for (Object o : keys) {
    // Access keys/values in a random order
    map.get(o);
}