public function getBoolean($key, $default = false, $deep = false)
    {
        return $this->filter($key, $default, $deep, FILTER_VALIDATE_BOOLEAN);
    }
public function getBoolean($key, $default = false, $deep = false)
    {
        return $this->filter($key, $default, $deep, FILTER_VALIDATE_BOOLEAN);
    }
public function getBoolean ( $ key , $ default = false , $ deep = false ) { return $ this -> filter ( $ key , $ default , $ deep , FILTER_VALIDATE_BOOLEAN ) ; }
Returns the parameter value converted to boolean.

@param string $key     The parameter key
@param mixed  $default The default value if the parameter key does not exist
@param bool   $deep    If true, a path like foo[bar] will find deeper items

@return bool The filtered value
Returns the parameter value converted to boolean .