is returned.

Examples
--------

SET @json = '[1, 2, [3, 4]]';

SELECT JSON_ARRAY_APPEND(@json, '$[0]', 5)
+-------------------------------------+
| JSON_ARRAY_APPEND(@json, '$[0]', 5) |
+-------------------------------------+
| [[1, 5], 2, [3, 4]]                 |
+-------------------------------------+

SELECT JSON_ARRAY_APPEND(@json, '$[1]', 6);
+-------------------------------------+
| JSON_ARRAY_APPEND(@json, '$[1]', 6) |
+-------------------------------------+
| [1, [2, 6], [3, 4]]                 |
+-------------------------------------+

SELECT JSON_ARRAY_APPEND(@json, '$[1]', 6, '$[2]', 7);
+------------------------------------------------+
| JSON_ARRAY_APPEND(@json, '$[1]', 6, '$[2]', 7) |
+------------------------------------------------+
| [1, [2, 6], [3, 4, 7]]                         |
+------------------------------------------------+

SELECT JSON_ARRAY_APPEND(@json, '$', 5);
+----------------------------------+
| JSON_ARRAY_APPEND(@json, '$', 5) |
+----------------------------------+
| [1, 2, [3, 4], 5]                |
+----------------------------------+

SET @json = '{"A": 1, "B": [2], "C": [3, 4]}';

SELECT JSON_ARRAY_APPEND(@json, '$.B', 5);
+------------------------------------+
| JSON_ARRAY_APPEND(@json, '$.B', 5) |
+------------------------------------+
| {"A": 1, "B": [2, 5], "C": [3, 4]} |
+------------------------------------+

URL: https://mariadb.com/kb/en/json_array_append/https://mariadb.com/kb/en/json_array_append/