---
title: "subscript(_:)"
framework: createml
role: symbol
role_heading: Instance Subscript
path: "createml/mldatacolumn/subscript(_:)-78irf"
---

# subscript(_:)

Creates a subset of the column by masking its elements with a column of Booleans.

## Declaration

```swift
subscript(mask: MLDataColumn<Bool>) -> MLDataColumn<Element> { get }
```

## Parameters

- `mask`: A Boolean column indicating whether elements should be kept (true) or removed (false) in the derived column.

## Return Value

Return Value A new column.

## See Also

### Masking elements to generate a column

- [subscript(_:)](createml/mldatacolumn/subscript(_:)-1n3x.md)