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# ARCOUNT

> Count the occupied slots in an array.

For sparse arrays, this differs from [ARLEN](./arlen), which returns the highest occupied index plus one.

## Arguments

<ParamField body="key" type="string" required>
  The array key.
</ParamField>

## Response

<ResponseField type="number" required>
  The number of slots containing values, or zero for a missing key.
</ResponseField>

<RequestExample>
```ts Example
await redis.arset("readings", 1000, "sample");
console.log(await redis.arcount("readings")); // 1
console.log(await redis.arlen("readings")); // "1001"
```
</RequestExample>

See the [server command reference](/redis/commands/array/arcount) for protocol details.