This function is
EXPERIMENTAL. The behaviour of this function, the
name of this function, and anything else documented about this
function may change without notice in a future release of PHP.
Use this function at your own risk.
Value to filter, arrays are filtered resursivelly.
ID of a filter to use.
Associative array of options or bitwise disjunction of flags. If filter
accepts options, flags can be provided in "flags" field of array. For
the "callback" filter, callback type should be passed.
Character set used for filtering. Currently no filter uses this