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JSON.ARRLEN

content/commands/json.arrlen.md

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Report the length of the JSON array at path in key

Examples

Required arguments

<details open><summary><code>key</code></summary>

is key to parse.

</details>

Optional arguments

<details open><summary><code>path</code></summary>

is JSONPath to specify. Default is root $, if not provided. Returns null if the key or path do not exist.

</details>

Examples

<details open> <summary><b>Get lengths of JSON arrays in a document</b></summary>

Create a document for wireless earbuds.

{{< highlight bash >}} redis> JSON.SET item:2 $ '{"name":"Wireless earbuds","description":"Wireless Bluetooth in-ear headphones","connection":{"wireless":true,"type":"Bluetooth"},"price":64.99,"stock":17,"colors":["black","white"], "max_level":[80, 100, 120]}' OK {{< / highlight >}}

Find lengths of arrays in all objects of the document.

{{< highlight bash >}} redis> JSON.ARRLEN item:2 '$.[*]'

  1. (nil)
  2. (nil)
  3. (nil)
  4. (nil)
  5. (nil)
  6. (integer) 2
  7. (integer) 3 {{< / highlight >}}

Return the length of the max_level array.

{{< highlight bash >}} redis> JSON.ARRLEN item:2 '$..max_level'

  1. (integer) 3 {{< / highlight >}}

Get all the maximum level values.

{{< highlight bash >}} redis> JSON.GET item:2 '$..max_level' "[[80,100,120]]" {{< / highlight >}}

</details>

Redis Software and Redis Cloud compatibility

| Redis Software | Redis Cloud | <span style="min-width: 9em; display: table-cell">Notes</span> | |:----------------------|:-----------------|:------| | <span title="Supported">✅ Supported</span> | <span title="Supported">✅ Flexible & Annual</span> <span title="Supported">✅ Free & Fixed</nobr></span> | |

Return information

{{< multitabs id="json-arrlen-return-info" tab1="RESP2" tab2="RESP3" >}}

With $-based path argument: [Array reply]({{< relref "/develop/reference/protocol-spec#arrays" >}}) of [integer replies]({{< relref "/develop/reference/protocol-spec#integers" >}}) or [null replies]({{< relref "/develop/reference/protocol-spec#nulls" >}}), where each element is the array length, or null if the matching value is not an array.

With .-based path argument: [Integer reply]({{< relref "/develop/reference/protocol-spec#integers" >}}) representing the array length, or [null reply]({{< relref "/develop/reference/protocol-spec#nulls" >}}) if the matching value is not an array.

-tab-sep-

With $-based path argument (default): [Array reply]({{< relref "/develop/reference/protocol-spec#arrays" >}}) of [integer replies]({{< relref "/develop/reference/protocol-spec#integers" >}}) or [null replies]({{< relref "/develop/reference/protocol-spec#nulls" >}}), where each element is the array length, or null if the matching value is not an array.

With .-based path argument: [Integer reply]({{< relref "/develop/reference/protocol-spec#integers" >}}) representing the array length, or [null reply]({{< relref "/develop/reference/protocol-spec#nulls" >}}) if the matching value is not an array.

{{< /multitabs >}}

See also

[JSON.ARRINDEX]({{< relref "commands/json.arrindex/" >}}) | [JSON.ARRINSERT]({{< relref "commands/json.arrinsert/" >}})

  • [RedisJSON]({{< relref "/develop/data-types/json/" >}})
  • [Index and search JSON documents]({{< relref "/develop/ai/search-and-query/indexing/" >}})