Alpha validates if a string contains English letters only (a-zA-Z).

Alphanumeric validates if a string contains English letters and digits only (a-zA-Z0-9).

ASCII validates if a string contains ASCII characters only.

Base64 validates if a string is encoded in Base64.

CountryCode2 validates if a string is a valid ISO3166 Alpha 2 country code.

CountryCode3 validates if a string is a valid ISO3166 Alpha 3 country code.

CreditCard validates if a string is a valid credit card number.

CurrencyCode validates if a string is a valid IsISO4217 currency code.

DataURI validates if a string is a valid base64-encoded data URI.

DialString validates if a string is a valid dial string that can be passed to Dial().

Digit validates if a string contains digits only (0-9).

DNSName validates if a string is valid DNS name.

Domain validates if a string is valid domain.

E164 validates if a string is a valid ISO3166 Alpha 2 country code.

Email validates if a string is an email or not.

EmailFormat validates if a string is an email or not.

ErrAlpha is the error that returns in case of an invalid alpha value.

ErrAlphanumeric is the error that returns in case of an invalid alphanumeric value.

ErrASCII is the error that returns in case of an invalid ASCII.

ErrBase64 is the error that returns in case of an invalid base54 value.

ErrCountryCode2 is the error that returns in case of an invalid two-letter country code.

ErrCountryCode3 is the error that returns in case of an invalid three-letter country code.

ErrCreditCard is the error that returns in case of an invalid credit card number.

ErrCurrencyCode is the error that returns in case of an invalid currency code.

ErrDataURI is the error that returns in case of an invalid data URI.

ErrDialString is the error that returns in case of an invalid string.

ErrDigit is the error that returns in case of an invalid digit value.

ErrDNSName is the error that returns in case of an invalid DNS name.

ErrDomain is the error that returns in case of an invalid domain.

ErrE164 is the error that returns in case of an invalid e165.

ErrEmail is the error that returns in case of an invalid email.

ErrFloat is the error that returns in case of an invalid float value.

ErrFullWidth is the error that returns in case of an invalid full-width value.

ErrHalfWidth is the error that returns in case of an invalid half-width value.

ErrHexadecimal is the error that returns in case of an invalid hexadecimal number.

ErrHexColor is the error that returns in case of an invalid hexadecimal color code.

ErrHost is the error that returns in case of an invalid host.

ErrInt is the error that returns in case of an invalid integer value.

ErrIP is the error that returns in case of an invalid IP.

ErrIPv4 is the error that returns in case of an invalid IPv4.

ErrIPv6 is the error that returns in case of an invalid IPv6.

ErrISBN is the error that returns in case of an invalid ISBN value.

ErrISBN10 is the error that returns in case of an invalid ISBN-10 value.

ErrISBN13 is the error that returns in case of an invalid ISBN-13 value.

ErrJSON is the error that returns in case of an invalid JSON.

ErrLatitude is the error that returns in case of an invalid latitude.

ErrLongitude is the error that returns in case of an invalid longitude.

ErrLowerCase is the error that returns in case of an invalid lower case value.

ErrMac is the error that returns in case of an invalid mac address.

ErrMongoID is the error that returns in case of an invalid MongoID.

ErrMultibyte is the error that returns in case of an invalid multibyte value.

ErrPort is the error that returns in case of an invalid port.

ErrPrintableASCII is the error that returns in case of an invalid printable ASCII value.

ErrRequestURI is the error that returns in case of an invalid request URI.

ErrRequestURL is the error that returns in case of an invalid request URL.

ErrRGBColor is the error that returns in case of an invalid RGB color code.

ErrSemver is the error that returns in case of an invalid semver.

ErrSSN is the error that returns in case of an invalid SSN.

ErrSubdomain is the error that returns in case of an invalid subdomain.

ErrUpperCase is the error that returns in case of an invalid upper case value.

ErrURL is the error that returns in case of an invalid URL.

ErrUTFDigit is the error that returns in case of an invalid utf digit value.

ErrUTFLetter is the error that returns in case of an invalid utf letter value.

ErrUTFLetterNumeric is the error that returns in case of an invalid utf numeric or letter value.

ErrUTFNumeric is the error that returns in case of an invalid utf numeric value.

ErrUUID is the error that returns in case of an invalid UUID value.

ErrUUIDv3 is the error that returns in case of an invalid UUIDv3 value.

ErrUUIDv4 is the error that returns in case of an invalid UUIDv4 value.

ErrUUIDv5 is the error that returns in case of an invalid UUIDv5 value.

ErrVariableWidth is the error that returns in case of an invalid variable width value.

Float validates if a string is a floating point number.

FullWidth validates if a string contains full-width characters.

HalfWidth validates if a string contains half-width characters.

Hexadecimal validates if a string is a valid hexadecimal number.

HexColor validates if a string is a valid hexadecimal color code.

Host validates if a string is a valid IP (both v4 and v6) or a valid DNS name.

Int validates if a string is a valid integer number.

IP validates if a string is a valid IP address (either version 4 or 6).

IPv4 validates if a string is a valid version 4 IP address.

IPv6 validates if a string is a valid version 6 IP address.

ISBN validates if a string is an ISBN (either version 10 or 13).

ISBN10 validates if a string is an ISBN version 10.

ISBN13 validates if a string is an ISBN version 13.

JSON validates if a string is in valid JSON format.

Latitude validates if a string is a valid latitude.

Longitude validates if a string is a valid longitude.

LowerCase validates if a string contains lower case unicode letters only.

MAC validates if a string is a MAC address.

MongoID validates if a string is a valid Mongo ID.

Multibyte validates if a string contains multibyte characters.

Port validates if a string is a valid port number.

PrintableASCII validates if a string contains printable ASCII characters only.

RequestURI validates if a string is a valid request URI.

RequestURL validates if a string is a valid request URL.

RGBColor validates if a string is a valid RGB color in the form of rgb(R, G, B).

Semver validates if a string is a valid semantic version.

SSN validates if a string is a social security number (SSN).

Subdomain validates if a string is valid subdomain.

UpperCase validates if a string contains upper case unicode letters only.

URL validates if a string is a valid URL.

UTFDigit validates if a string contains unicode decimal digits only.

UTFLetter validates if a string contains unicode letters only.

UTFLetterNumeric validates if a string contains unicode letters and numbers only.

UTFNumeric validates if a string contains unicode number characters (category N) only.

UUID validates if a string is a valid UUID.

UUIDv3 validates if a string is a valid version 3 UUID.

UUIDv4 validates if a string is a valid version 4 UUID.

UUIDv5 validates if a string is a valid version 5 UUID.

VariableWidth validates if a string contains both full-width and half-width characters.