isEmail( $email)
isUrl( $url)
isPhone( $phone)
isIP( $ip, $version = null)
isNumber( $number)
hasNumber( $number)
isPrice( $price, $precise = 2)
isEnglish( $string)
hasEnglish( $string)
isChinese( $string)
hasChinese( $string)
isDate( $date, $formats = array('Y-m-d', 'Y/m/d'))
isJson( $string)