# columnGroupShow

Chooses whether the column appears when its parent group is expanded or collapsed.

Canonical: https://grid.syidax.com/docs/columns/columnGroupShow/

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## What does this API do?

Chooses whether the column appears when its parent group is expanded or collapsed.

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## Exact input and result types

```typescript
columnGroupShow?: 'open' | 'closed'
```

| Item | Value |
| --- | --- |
| Required | Optional |
| Input type | 'open' \| 'closed' |

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## Usage flow

Set this on an individual column object in columnDefs. Pass arrays, objects, and callbacks through JavaScript, and use new arrays or objects when applying changes.

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## Feature explanations and examples

- [Multi-level headers](https://grid.syidax.com/docs/features/column-groups.md) — Multi-level headers place related columns under a shared heading. Unlike row grouping, they do not change data counts or aggregate values.