## Overview

This module provides APIs to generate and inspect UUIDs (Universally Unique Identifiers).

The UUIDs are generated based on the [RFC 4122](https://www.rfc-editor.org/rfc/rfc4122.html) standard. This module supports generating 4 versions of UUIDs.

### Version 1

Generated using the MAC address of the computer and the time of generation.

### Version 3

Cryptographic hashing and application-provided text strings are used to generate a UUID. MD5 hashing is used.

### Version 4

Uses a pseudo-random number generator to generate the UUID. Every bit of the string is randomly generated.

### Version 5

Similar to Version 3 but uses SHA-1 instead of MD5.

Other operations include validating a given UUID string and getting the version of a UUID string.

For information on the operations, which you can perform with the `uuid` module, see the below **Functions**.


Represents UUIDs strings of well known namespace IDs.



Namespace is a fully-qualified domain name


NAME_SPACE_DNS

NAME_SPACE_URL

NAME_SPACE_OID

Namespace is an X.500 DN (in DER or a text output format)


NAME_SPACE_X500

NAME_SPACE_NIL

NamespaceUUID

UUID generated using the MAC address of the computer and the time of generation


UUID generated using MD5 hashing and application-provided text string


UUID generated using a pseudo-random number generator


UUID generated using SHA-1 hashing and application-provided text string


Version

Error

Returns a UUID of type 1 as a UUID record.
```ballerina
uuid:Uuid uuid1 = check uuid:createType1AsRecord();
```



createType1AsRecord

UUID of type 1 as a UUID record, or else a `uuid:Error`


Uuid

Returns a UUID of type 1 as a string.
```ballerina
string uuid1 = uuid:createType1AsString();
```



createType1AsString

string

Returns a UUID of type 3 as a UUID record.
```ballerina
uuid:Uuid uuid3 = check uuid:createType3AsRecord(uuid:NAME_SPACE_DNS, “ballerina.io”);
```



createType3AsRecord

String representation for a pre-defined namespace UUID


namespace

name

UUID of type 3 as a UUID record, or else a `uuid:Error`


Returns a UUID of type 3 as a string.
```ballerina
string uuid3 = check uuid:createType3AsString(uuid:NAME_SPACE_DNS, “ballerina.io”);
```



createType3AsString

UUID of type 3 as a string, or else a `uuid:Error`


Returns a UUID of type 4 as a UUID record.
```ballerina
uuid:Uuid uuid4 = check uuid:createType4AsRecord();
```



createType4AsRecord

UUID of type 4 as a UUID record, or else a `uuid:Error`


Returns a UUID of type 4 as a string.
```ballerina
string uuid4 = uuid:createType4AsString();
```



createType4AsString

Returns a UUID of type 5 as a UUID record.
```ballerina
uuid:Uuid uuid5 = check uuid:createType5AsRecord(uuid:NAME_SPACE_DNS, “ballerina.io”);
```



createType5AsRecord

UUID of type 5 as a UUID record, or else a `uuid:Error`


Returns a UUID of type 5 as a string.
```ballerina
string uuid5 = check uuid:createType5AsString(uuid:NAME_SPACE_DNS, “ballerina.io”);
```



createType5AsString

UUID of type 5 as a string, or else a `uuid:Error`


Detect RFC version of a UUID. Returns an error if the UUID is invalid.
```ballerina
uuid:Version v = check uuid:getVersion("4397465e-35f9-11eb-adc1-0242ac120002");
```



getVersion

uuid

Returns a nil UUID as a UUID record.
```ballerina
uuid:Uuid nilUUID = uuid:nilAsRecord();
```



nilAsRecord

Returns a nil UUID as a string.
```ballerina
string nilUUID = uuid:nilAsString();
```



nilAsString

Converts to an array of bytes. Returns an error if the UUID is invalid.
```ballerina
byte[] b = check uuid:toBytes(“6ec0bd7f-11c0-43da-975e-2aesass0b”);
```



toBytes

Converts to a UUID record. Returns an error if the UUID is invalid.
```ballerina
uuid:Uuid r1 = check uuid:toRecord("4397465e-35f9-11eb-adc1-0242ac120002");
uuid:Uuid r2 = check uuid:toRecord([10, 20, 30]);
```



toRecord

Converts to a UUID string. Returns an error if the UUID is invalid.
```ballerina
string s = check uuid:toString([5, 12, 16, 35]);
```



toString

error

Test a string to see if it is a valid UUID.
```ballerina
boolean valid = uuid:validate("4397465e-35f9-11eb-adc1-0242ac120002");
```



validate

boolean

timeLow

Unsigned32

timeMid

Unsigned16

The high field of the timestamp multiplexed with the version number


timeHiAndVersion

The high field of the clock sequence multiplexed with the variant


clockSeqHiAndReserved

Unsigned8

clockSeqLo

node

This module provides APIs to generate and inspect UUIDs (Universally Unique Identifiers).


Record: Uuid

Fields