redis SCARD command
Translation results：
UK [s'kɑ:rd] US [s'kɑ:rd]
abbr.signal conditioning and recording device signal conditioning and recording device
redis SCARD commandsyntax
Function: Return the cardinality of the set key (the number of elements in the set).
Syntax: SCARD key
Available versions: >= 1.0.0
Time complexity: O(1)
Returns: The cardinality of the set. When key does not exist, return 0.
redis SCARD commandexample
redis> SADD tool pc printer phone (integer) 3 redis> SCARD tool # 非空集合 (integer) 3 redis> DEL tool (integer) 1 redis> SCARD tool # 空集合 (integer) 0