---
title: "summary(of:)"
framework: tabulardata
role: symbol
role_heading: Instance Method
path: "tabulardata/rowgroupingprotocol/summary(of:)"
---

# summary(of:)

Generates a group summaries instance of the row grouping’s columns you select by name.

## Declaration

```swift
func summary(of columnNames: [String]) -> any GroupSummaries
```

## Parameters

- `columnNames`: An array of column names.

## See Also

### Summarizing a Row Grouping

- [summary()](tabulardata/rowgroupingprotocol/summary().md)
- [GroupSummaries](tabulardata/groupsummaries.md)