bit

英[bɪt] 美[bɪt]

n. A little bit, a piece; a small amount, a little; a while, a blink of an eye; [count] bit ( Binary information unit)

adj. very small, insignificant

adv. [colloquial] quite, a little, more or less, how much [a bit to omitted]

vt. To put a bit on (the horse); to put on the bit; to restrain; to restrict

v. to bite, sting (past tense of bite); to sting; to bite bait; to have a bite (or sting) Habit

Third person singular: bits Plural: bits Present participle: bitting Past tense: bitted Past participle: bitted

op

英[ɒp ] 美[ɑ:p]

n.Work, operation

plural: ops

redis BITOP command syntax

Function: Perform bit operations on one or more string keys that store binary bits, and save the results to destkey.

Syntax: BITOP operation destkey key [key ...]

Description: When BITOP handles strings of different lengths, the shorter The missing part of that string will be treated as 0 . An empty key is also treated as a sequence of strings containing 0's.

Available versions: >= 2.6.0

Time complexity: O(N)

Return: The length of the string saved to destkey is equal to the length of the longest string in the input key.

redis BITOP command example

redis> SETBIT bits-1 0 1        # bits-1 = 1001
(integer) 0
redis> SETBIT bits-1 3 1
(integer) 0
redis> SETBIT bits-2 0 1        # bits-2 = 1011
(integer) 0
redis> SETBIT bits-2 1 1
(integer) 0
redis> SETBIT bits-2 3 1
(integer) 0
redis> BITOP AND and-result bits-1 bits-2
(integer) 1
redis> GETBIT and-result 0      # and-result = 1001
(integer) 1
redis> GETBIT and-result 1
(integer) 0
redis> GETBIT and-result 2
(integer) 0
redis> GETBIT and-result 3
(integer) 1