Parsing JSONObject having dynamic key

I have following JSON as response from my server. At first, I thought, it was invalid JSON but after validating it, it seems to be correct:

JOSN: {
    "category": {
        "1": "World",
        "2": "Politics",
        "3": "Economy",
        "4": "Sports",
        "5": "Cricket",
        "6": "General",
        "7": "Business",
        "8": "Services",
        "9": "Law & Order",
        "10": "Entertainment"
    }
}

if keys inside category JSONObject is dynamic then use JSONObject.keys() to get Iterator for getting values as:

JSONObject mainJSONObj=new JSONObject(<json_string>);
// get category JSONObject from mainJSONObj
JSONObject categoryJSONObj=mainJSONObj.getJSONObject("category");

// get all keys from categoryJSONObj

Iterator<String> iterator = categoryJSONObj.keys();
  while (iterator.hasNext()) {
    String key = iterator.next();
    Log.i("TAG","key:"+key +"--Value::"+categoryJSONObj.optString(key);
  }

Use the keys() iterator to iterate over all the properties, and call get() for each.
Iterator<String> iter = json.keys();
while (iter.hasNext()) {
    String key = iter.next();
    try {
        Object value = json.get(key);
    } catch (JSONException e) {
        // Something went wrong!
    }
}