How do I get the size of a set on Redis?

Question

For lists I can do the operation:

LLEN KeyName

and it will return the size of a list in Redis. What is the equivalent command for sets? I can't seem to find this in any documentation.

Answer 1

You are looking for the SCARD command:

SCARD key

Returns the set cardinality (number of elements) of the set stored at

Return value
Integer reply: the cardinality (number of elements) of the set, or 0 if key does not exist.

You can view all of the set commands on the documentation webpage.

Answer 2

If it's a sorted set, you can use

ZCOUNT myset -inf +inf

or

ZCARD myset

Answer 3

• zCard is short for cardinality (cardinality is the number of elements in a set). It gives you total number of members inside of a "sorted set".

• Sometimes you might wanna extract how many members are inside of a range in a sorted set. For that you can use zCount.

  ZCOUNT cars 0 50  // inclusive
  

this will include 0 and 55. 0 <= .... <=50. But if you do not want to include them

ZCOUNT cars (0 (50

• if it is regular set

  SCARD cars