JSON.ARRLEN key [path]

Available in: Redis Stack

Time complexity: O(1) where path is evaluated to a single value, O(N) where path is evaluated to multiple values, where N is the size of the key

Reports the length of the JSON Array at path in key.

path defaults to root if not provided. Returns null if the key or path do not exist.

Return

[] if the matching JSON value is not an array.

redis> JSON.SET doc $ '{"a":[3], "nested": {"a": [3,4]}}'
OK
redis> JSON.ARRLEN doc $..a
1) (integer) 1
2) (integer) 2

redis> JSON.SET doc $ '{"a":[1,2,3,2], "nested": {"a": false}}'
OK
redis> JSON.ARRLEN doc $..a
1) (integer) 4
2) (nil)