---
title: "prefix(_:)"
framework: createml
role: symbol
role_heading: Instance Method
path: "createml/mldatacolumn/prefix(_:)"
---

# prefix(_:)

Creates a subset of the column, given a number of initial elements.

## Declaration

```swift
func prefix(_ maxLength: Int = 10) -> MLDataColumn<Element>
```

## Parameters

- `maxLength`: An integer that limits the number of elements to use from the beginning of the column. The default value is 10.

## Return Value

Return Value A new column.

## See Also

### Selecting elements to generate a column

- [subscript(_:)](createml/mldatacolumn/subscript(_:)-pp34.md)
- [subscript(_:)](createml/mldatacolumn/subscript(_:)-5mczv.md)
- [suffix(_:)](createml/mldatacolumn/suffix(_:).md)