15 lines
956 B
Markdown
15 lines
956 B
Markdown
# UUID v4
|
||
|
||
Anything on the Socialbox world that needs to be uniquely identified with a random identifier must use the UUID V4
|
||
specification. UUID v4 is a randomly generated identifier that consists of 32 hexadecimal digits separated by hyphens.
|
||
|
||
---
|
||
|
||
A version 4 UUID is randomly generated. As in other UUIDs, 4 bits are used to indicate version 4, and 2 or 3 bits to
|
||
indicate the variant (102 or 1102 for variants 1 and 2 respectively). Thus, for variant 1 (that is, most UUIDs) a
|
||
random version 4 UUID will have 6 predetermined variant and version bits, leaving 122 bits for the randomly generated
|
||
part, for a total of 2122, or 5.3×1036 (5.3 undecillion) possible version-4 variant-1 UUIDs. There are half as many
|
||
possible version 4, variant 2 UUIDs (legacy GUIDs) because there is one less random bit available, 3 bits being
|
||
consumed for the variant.
|
||
|
||
Source: [Wikipedia](https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_(random))
|