Best structure for list of key-value (integer, string) to be shuffled
You can keep the Map. The Map is designed to be looked up by key so I suggest you have a list of shuffled keys.
public Map<Integer, String> getQuestionOptionsMap() {
Map<Integer, String> map = new HashMap<>();
String[] answers = {null, answer1, answer2, answer3, answer4};
for (int i = 1; i < answers.length; i++)
if (answers[i] != null)
map.put(i, answers[i]);
List<Integer> order = new ArrayList<>(map.keySet());
Collections.shuffle(order);
Map<Integer, String> shuffled = new LinkedHashMap<>();
for (Integer key : order)
shuffled.put(key, map.get(key));
return shuffled;
}
Create a Pair
class, that holds both the Integer
and the String
and then add multiple Pair
objects to a List, which will be shuffled.
public class Pair {
private Integer integer;
private String string;
//accessors
}
Then:
List<Pair> list = new ArrayList<Pair>();
//...add some Pair objects to the list
Collections.shuffle(list);
You could keep a separate List
of the keyvalues, shuffle that and use it to access the HashMap
.
List<Integer> keys = new ArrayList<Integer>(map.keySet());
Collections.shuffle(keys);
for(Integer i : keys)
map.get(i); // Gets the values in the shuffled order