How to get the keys from a LinkedHasMap?

Question

I have a code populating a listView:

JSONArray data = responseData.getJSONArray("data");
String[] values = new String[data.length()];//I wanna get rid of this

LinkedHashMap<String, String> helpData = new LinkedHashMap();
for (int i = 0; i < data.length() ; i++) {
  String header = data.getJSONObject(i).getString("glossary_header");
  String description = data.getJSONObject(i).getString("gloassary_description");

  helpData.put(header, description);
    values[i] = header;
  Log.d("mylog", "counter" + i);
}

ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
        android.R.layout.simple_list_item_1, values);
setListAdapter(adapter);

I want to pass the keys to Arrayadapter, I was hoping to find a getKeys() method that could magically return an array of key from the map.

KeySet() was close but did not work, what is the proper way to do this. I don't want to use string array. I want to have my pair values together.

Answer 1

Set<String> keys = myArray.keySet();
String[] keysAsArray = keys.toArray(new String[0]);

More detail on the toArray method can be found at http://docs.oracle.com/javase/7/docs/api/java/util/Set.html#toArray(T[])

Answer 2

You can get like this

   Collection<String> values = helpData.keySet();

     for (String string : values) {
           //
       }

Answer 3

for (final String key : helpData.keySet()) {
  // print data...
}

or

final Iterator<String> cursor = helpData.keySet().iterator();
while (cursor.hasNext()) {
  final String key = cursor.next();
 // Print data
}