JSON.ARRPOP
JSON.ARRPOP key [path [index]]
- Available in:
- Redis CE / JSON 1.0.0
- Time complexity:
- O(N) when path is evaluated to a single value where N is the size of the array and the specified index is not the last element, O(1) when path is evaluated to a single value and the specified index is the last element, or O(N) when path is evaluated to multiple values, where N is the size of the key
- ACL categories:
-
@json
,@write
,@slow
,
Remove and return an element from the index in the array
Required arguments
key
is key to modify.
index
is position in the array to start popping from. Default is -1
, meaning the last element. Out-of-range indexes round to their respective array ends. Popping an empty array returns null.
Optional arguments
path
is JSONPath to specify. Default is root $
.
Return
JSON.ARRPOP
returns an array of bulk string replies for each path, each reply is the popped JSON value, or nil
, if the matching JSON value is not an array.
For more information about replies, see Redis serialization protocol specification.
Examples
Pop a value from an index and insert a new value
Create two headphone products with maximum sound levels.
redis> JSON.SET key $ '[{"name":"Healthy headphones","description":"Wireless Bluetooth headphones with noise-cancelling technology","connection":{"wireless":true,"type":"Bluetooth"},"price":99.98,"stock":25,"colors":["black","silver"],"max_level":[60,70,80]},{"name":"Noisy headphones","description":"Wireless Bluetooth headphones with noise-cancelling technology","connection":{"wireless":true,"type":"Bluetooth"},"price":99.98,"stock":25,"colors":["black","silver"],"max_level":[80,90,100,120]}]'
OK
Get all maximum values for the second product.
redis> JSON.GET key $.[1].max_level
"[[80,90,100,120]]"
Update the max_level
field of the product: remove an unavailable value and add a newly available value.
redis> JSON.ARRPOP key $.[1].max_level 0
1) "80"
Get the updated array.
redis> JSON.GET key $.[1].max_level
"[[90,100,120]]"
Now insert a new lowest value.
redis> JSON.ARRINSERT key $.[1].max_level 0 85
1) (integer) 4
Get the updated array.
redis> JSON.GET key $.[1].max_level
"[[85,90,100,120]]"
See also
JSON.ARRAPPEND
| JSON.ARRINDEX