Joomla! Documentation™

When considering user input you should think about the data type you are expecting to retrieve and apply the most stringent form of JInput that is applicable in each case. In particular, avoid the lazy approach of using JInput->get as this will return an array that may contain entries that you did not expect and although each of those entries will have been cleaned, it is often the case that additional filtering could have been applied to some individual arguments. For example, the get method treats all arguments as strings, whereas it may be possible to restrict some arguments to be integers.