Does java.util.UUID.randomUUID().toString() length always equal to 36?
I was not able to find info on that. Here it is said only the following:
For those like me that start googling before reading the javadoc, here the javadoc ;)
UUID.toString
For those that Don't know how to read a grammar tree read from Bottom to Top.
an hexDigit is one char
an hexOctet is 2 hexDigits = 2chars
a node is 6 * hexOctet = 6 * 2hexdigit = 6*2 chars = 12chars
a variant_and_sequence is 2 * hexOctet = 2 * 2hexdigit = 2*2 chars = 4chars
a time_high_and_version is 2 * hexOctet = 2 * 2hexdigit = 2*2 chars = 4chars
a time_mid is 2 * hexOctet = 2 * 2hexdigit = 2*2 chars = 4chars
a time_low is 4 * hexOctet = 4* 2hexdigit = 4*2 chars = 8chars
and finaly, a UUID is < time_low > "-" < time_mid > "-" < time_high_and_version > "-" < variant_and_sequence > "-"< node >
= 8 chars + 1 char + 4 chars + 1 char + 4 chars + 1 char + 4 chars + 1 char + 12 chars
= 36 chars ! 128 bit of data + 4 hyphen as stated previously
The UUID string representation is as described by this BNF:
UUID = "-" "-"
"-"
"-"
time_low = 4*
time_mid = 2*
time_high_and_version = 2*
variant_and_sequence = 2*
node = 6*
hexOctet =
hexDigit =
"0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
| "a" | "b" | "c" | "d" | "e" | "f"
| "A" | "B" | "C" | "D" | "E" | "F"