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> Reference material for ARRAY_COUNT_DISTINCT function

# ARRAY_COUNT_DISTINCT

Returns the number of distinct (unique) elements in the array. As with `COUNT` and `COUNT(DISTINCT ...)` aggregations, `NULL` is not counted as a value if it occurs.

## Syntax

```sql theme={"theme":{"light":"css-variables","dark":"css-variables"}}
ARRAY_COUNT_DISTINCT(<array>)
```

## Parameters

| Parameter | Description                                        | Supported input types |
| :-------- | :------------------------------------------------- | :-------------------- |
| `<array>` | The array of which to count the distinct elements. | Any `ARRAY` type      |

## Return Type

`INTEGER`

## Example

<div className="query-window">
  ```
  SELECT ARRAY_COUNT_DISTINCT([1, 2, 4, 5, 2, NULL, 5, 1]) AS res;
  ```

  | res <span>int</span> |
  | :------------------- |
  | 4                    |

  <p><span>Rows: 1</span><span>Execution time: 5.78ms</span></p>
</div>