HLEN command in redis

HLEN key

Return the number of entries (fields) contained in the hash stored at the key. If the specified key does not exist, 0 is returned assuming an empty hash.

TIME COMPLEXITY: O(1)

RETURN VALUE: It returns an integer value number of entries.

Syntax:

HLEN KEY_NAME

Example 1: When the key is present.

redis:6379> HSET myhash field2 100
(integer) 1
redis:6379> HSET myhash field 200
(integer) 1

redis:6379> HLEN myhash
(integer) 2

Output

2

Example 2: When the key is not present.

redis:6379> HLEN myhashkey
(integer) 0

Output

0