# CategoricalSummary A categorical summary of a collection’s elements. ``` struct CategoricalSummary where Element : Hashable ``` ## Overview Each categorical summary has 5 statistics about a collection: - `someCount`: The number of non-missing elements. - `noneCount` The number of missing elements. - `uniqueCount`: The number of unique elements. - `totalCount`: The total number of elements. - `mode`: An array of the most common values. ## Topics ### Creating a Summary [`init()`](/documentation/TabularData/CategoricalSummary/init()) Creates a categorical summary with default values. [`init(someCount: Int, noneCount: Int, uniqueCount: Int, mode: [Element])`](/documentation/TabularData/CategoricalSummary/init(someCount:noneCount:uniqueCount:mode:)) Creates a categorical summary. ### Comparing Summaries ### Inspecting a Summary [`var debugDescription: String`](/documentation/TabularData/CategoricalSummary/debugDescription) A text representation of the summary’s statistics suitable for debugging. [`var mode: [Element]`](/documentation/TabularData/CategoricalSummary/mode) The most common values in a column, ignoring missing elements. [`var uniqueCount: Int`](/documentation/TabularData/CategoricalSummary/uniqueCount) The number of elements with distinct values in a column that excludes missing elements. [`var someCount: Int`](/documentation/TabularData/CategoricalSummary/someCount) The number of non-missing elements in the column. [`var noneCount: Int`](/documentation/TabularData/CategoricalSummary/noneCount) The number of missing elements in the column. [`var totalCount: Int`](/documentation/TabularData/CategoricalSummary/totalCount) The total number of elements in the column. ## Relationships ### Conforms To [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`Hashable`](/documentation/Swift/Hashable) [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Equatable`](/documentation/Swift/Equatable) --- 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)