# aggregationFn_uniqueCount

# Variable: aggregationFn\_uniqueCount

```ts
const aggregationFn_uniqueCount: AggregationFn<any, any>;
```

Defined in: [fns/aggregationFns.ts:215](https://github.com/TanStack/table/blob/main/packages/table-core/src/fns/aggregationFns.ts#L215)

Counts unique leaf-row values for a grouped column.

Values are compared with JavaScript `Set` semantics.