> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/reference/sql-functions/special-functions/json-functions/json_length.md).
# JSON\_LENGTH
## Syntax
```bnf
JSON_LENGTH(json_doc[, path])
```
## Description
Returns the length of a JSON document, or, if the optional path argument is given, the length of the value within the document specified by the path.
Returns `NULL` if any of the arguments argument are null or the path argument does not identify a value in the document.
An error occurs if the JSON document is invalid, the path is invalid or if the path contains a `*` or `**` wildcard.
Length will be determined as follow:
* A scalar's length is always 1.
* If an array, the number of elements in the array.
* If an object, the number of members in the object.
The length of nested arrays or objects are not counted.
## Examples
```
```
*This page is licensed: CC BY-SA / Gnu FDL*
{% @marketo/form formId="4316" %}
---
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