> For the complete documentation index, see [llms.txt](https://aiii-mike.gitbook.io/redis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://aiii-mike.gitbook.io/redis/command/list/llen.md).

# llen

### 1. 基本語法

#### llen**(`key` , `callback`)** 

回傳串列長度，**`key`**值不存在則回傳0。

{% tabs %}
{% tab title="TypeScript" %}

```typescript
client.del('foo');

const foo_list = ['Hello', 'Such', 'A', 'Beautiful', 'World'];
client.rpush('foo', foo_list);
client.llen('foo', redis.print);
```

{% endtab %}
{% endtabs %}

{% tabs %}
{% tab title="Output-TS" %}

```
Reply: 5
```

{% endtab %}
{% endtabs %}