How to detect the type of a JSON (JavaScript Object Notation) value using the JSON_TYPE() function?

JSON_TYPE(json) is a MySQL built-in function that returns the data type of a JSON (JavaScript Object Notation) value. For example:

SELECT JSON_TYPE('[]'), JSON_TYPE('{}');
  -- +-----------------+-----------------+
  -- | JSON_TYPE('[]') | JSON_TYPE('{}') |
  -- +-----------------+-----------------+
  -- | ARRAY           | OBJECT          |
  -- +-----------------+-----------------+

SELECT JSON_TYPE('null'), JSON_TYPE('true');
  -- +-------------------+-------------------+
  -- | JSON_TYPE('null') | JSON_TYPE('true') |
  -- +-------------------+-------------------+
  -- | NULL              | BOOLEAN           |
  -- +-------------------+-------------------+

SELECT JSON_TYPE('"FYI"'), JSON_TYPE('999');
  -- +--------------------+------------------+
  -- | JSON_TYPE('"FYI"') | JSON_TYPE('999') |
  -- +--------------------+------------------+
  -- | STRING             | INTEGER          |
  -- +--------------------+------------------+

Note that JSON_TYPE() does not return the official type NUMERIC on JSON numeric scalars. It actually returns the MySQL data type of any JSON numeric scalar. For example:

SELECT JSON_TYPE('999'), JSON_TYPE('9.99');
  -- +------------------+-------------------+
  -- | JSON_TYPE('999') | JSON_TYPE('9.99') |
  -- +------------------+-------------------+
  -- | INTEGER          | DOUBLE            |
  -- +------------------+-------------------+

Also note that the argument must be a valid JSON encoded MySQL string. Other MySQL values will result an error.

SELECT JSON_TYPE(999);
ERROR 3146 (22032): Invalid data type for JSON data in argument 1
to function json_type; a JSON string or JSON type is required.

Reference information of the JSON_TYPE() function:

JSON_TYPE(json): int
  Returns the data type of a JSON (JavaScript Object Notation) value.

Arguments, return value and availability:
  json: Required. The JSON value to be observed.
  int: Return value. The data type of the JSON value.
  Available since MySQL 5.7.

⇒ JSON_UNQUOTE() - Unquoting JSON String

⇐ JSON_TABLE() - Inline Table with JSON Array

⇑ MySQL Functions on JSON Values

⇑⇑ MySQL Function References