public JSONArray optJSONArray(String key){
  Object o=opt(key);
  return o instanceof JSONArray ? (JSONArray)o : null;
}

public JSONArray optJSONArray ( String key ) { Object o = opt ( key ) ; return o instanceof JSONArray ? ( JSONArray ) o : null ; }
get an optional jsonarray associated with a key . it returns null if there is unknown such key , or if its value is not a jsonarray .
