# TableColumnForEach A structure that computes columns on demand from an underlying collection of identified data. ``` nonisolated struct TableColumnForEach where Data : RandomAccessCollection, ID : Hashable, RowValue == Content.TableRowValue, Sort == Content.TableColumnSortComparator, Content : TableColumnContent ``` ## Overview Use `TableColumnForEach` to create columns based on a of some data type. Either the collection’s elements must conform to or you need to provide an `id` parameter to the `TableColumnForEach` initializer. The following example shows the interface for an `AudioSampleTrack`, which h as a collection of `AudioSample` across a dynamic number of `AudioChannel`s. The `Table` is created for displaying rows for each sample. It has one static column for the sample’s timestamp and uses a `TableColumnForEach` instance to produce a column for each of the audio channels in the track. ``` struct AudioChannel: Identifiable { let name: String let id: UUID } struct AudioSample: Identifiable { let id: UUID let timestamp: TimeInterval func level(channel: AudioChannel.ID) -> Double } @Observable class AudioSampleTrack { let channels: [AudioChannel] var samples: some RandomAccessCollection { get } } struct ContentView: View { var track: AudioSampleTrack var body: some View { Table(track.samples) { TableColumn("Timestamp (ms)") { sample in Text(sample.timestamp, format: .number.scale(1000)) .monospacedDigit() } TableColumnForEach(track.channels) { channel in TableColumn(channel.name) { sample in Text(sample.level(channel: channel.id), format: .number.precision(.fractionLength(2)) ) .monospacedDigit() } .width(ideal: 70) .alignment(.numeric) } } } } ``` ## Topics ### Creating the collection [`init ( _ : content :)`](/documentation/SwiftUI/TableColumnForEach/init(_:content:)) Creates an instance that uniquely identifies and creates table columns across updates based on the identity of the underlying data. [`init(_:id:content:)`](/documentation/SwiftUI/TableColumnForEach/init(_:id:content:)) Creates an instance that uniquely identifies and creates table columns across updates based on the provided key path to the underlying data’s identifier. ### Accessing collection content [`content`](/documentation/SwiftUI/TableColumnForEach/content) A function to create content on demand using the underlying data. [`data`](/documentation/SwiftUI/TableColumnForEach/data) The collection of underlying identified data that SwiftUI uses to create columns dynamically. ## Relationships ### Conforms To [`TableColumnContent`](/documentation/SwiftUI/TableColumnContent) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)