# OptionalColumnProtocol A type that represents a column that has missing values. ``` protocol OptionalColumnProtocol : ColumnProtocol ``` ## Overview `OptionalColumnProtocol` defines the common functionality for column types that support missing values. ## Topics ### Filling an Optional Column [`func filled(with: Self.WrappedElement) -> FilledColumn`](/documentation/TabularData/OptionalColumnProtocol/filled(with:)) Generates a filled column by replacing missing elements with a value. ### Generating an Optional Column by Adding Two Columns [`static func + (Self, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/+(_:_:)-2qex0) Generates a column by adding each element in an optional column type to the corresponding elements of another. [`func + (L, R) -> Column`](/documentation/TabularData/+(_:_:)-1i7oh) Generates a column by adding each element in a column type to the corresponding elements of an optional column type. [`func + (L, R) -> Column`](/documentation/TabularData/+(_:_:)-3exmp) Generates a column by adding each element in an optional column type to the corresponding elements of a column type. ### Generating an Optional Column by Subtracting Two Columns [`static func - (Self, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/-(_:_:)-5xfkx) Generates a column by subtracting each element in an optional column type from the corresponding elements of another. [`func - (L, R) -> Column`](/documentation/TabularData/-(_:_:)-25cs6) Generates a column by subtracting each element in an optional column type from the corresponding elements of a column type. [`func - (L, R) -> Column`](/documentation/TabularData/-(_:_:)-95yoe) Generates a column by subtracting each element in a column type from the corresponding elements of an optional column. ### Generating an Optional Column by Multiplying Two Columns [`static func * (Self, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/*(_:_:)-5f5kx) Generates a column by multiplying each element in an optional column type by the corresponding elements of another. [`func * (L, R) -> Column`](/documentation/TabularData/*(_:_:)-2toor) Generates a column by multiplying each element in an optional column type by the corresponding elements of a column type. [`func * (L, R) -> Column`](/documentation/TabularData/*(_:_:)-l9r3) Generates a column by multiplying each element in a column type by the corresponding elements of an optional column type. ### Generating an Optional Column by Dividing Two Columns [`static func / (Self, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-4nmnl) Generates an integer column by dividing each element in an optional column type by the corresponding elements of another. [`func / (L, R) -> Column`](/documentation/TabularData/_(_:_:)-9v3nw) Generates an integer column by dividing each element in a column type by the corresponding elements of an optional column type. [`func / (L, R) -> Column`](/documentation/TabularData/_(_:_:)-4igyw) Generates an integer column by dividing each element in an optional column type by the corresponding elements of a column type. [`static func / (Self, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-3rlo3) Generates a floating-point column by dividing each element in an optional column type by the corresponding elements of another. [`func / (L, R) -> Column`](/documentation/TabularData/_(_:_:)-4pr65) Generates a floating-point column by dividing each element in a column type by the corresponding elements of an optional column type. [`func / (L, R) -> Column`](/documentation/TabularData/_(_:_:)-58kg6) Generates a floating-point column by dividing each element in an optional column type by the corresponding elements of a column type. ### Generating an Optional Column by Combining a Value [`static func + (Self, Self.WrappedElement) -> Column`](/documentation/TabularData/OptionalColumnProtocol/+(_:_:)-501gg) Generates a column by adding a value to each element in an optional column. [`static func + (Self.WrappedElement, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/+(_:_:)-6ko8x) Generates a column by adding each element in an optional column to a value. [`static func - (Self, Self.WrappedElement) -> Column`](/documentation/TabularData/OptionalColumnProtocol/-(_:_:)-9mejf) Generates a column by subtracting a value from each element in an optional column type. [`static func - (Self.WrappedElement, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/-(_:_:)-5vffa) Generates a column by subtracting each element in an optional column from a value. [`static func * (Self, Self.WrappedElement) -> Column`](/documentation/TabularData/OptionalColumnProtocol/*(_:_:)-orkq) Generates a column by multiplying each element in an optional column by a value. [`static func * (Self.WrappedElement, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/*(_:_:)-5vorv) Generates a column by multiplying a value by each element in an optional column type. [`static func / (Self, Self.WrappedElement) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-7tbmq) Generates an integer column by dividing each element in an optional column by a value. [`static func / (Self.WrappedElement, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-56h1d) Generates an integer column by dividing a value by each element in an optional column type. [`static func / (Self, Self.WrappedElement) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-5qhxr) Generates a floating-point column by dividing each element in an optional column by a value. [`static func / (Self.WrappedElement, Self) -> Column`](/documentation/TabularData/OptionalColumnProtocol/_(_:_:)-2xfqa) Generates a floating-point column by dividing a value by each element in an optional column type. ### Describing an Optional Column [`func description(options: FormattingOptions) -> String`](/documentation/TabularData/OptionalColumnProtocol/description(options:)) Generates a string description of the optional column type. ### Supporting Types [`associatedtype WrappedElement`](/documentation/TabularData/OptionalColumnProtocol/WrappedElement) The type of the optional column type’s elements. ## Relationships ### Inherits From [`ColumnProtocol`](/documentation/TabularData/ColumnProtocol) [`BidirectionalCollection`](/documentation/Swift/BidirectionalCollection) [`Collection`](/documentation/Swift/Collection) [`Sequence`](/documentation/Swift/Sequence) ### Conforming Types [`Column`](/documentation/TabularData/Column) [`ColumnSlice`](/documentation/TabularData/ColumnSlice) [`DiscontiguousColumnSlice`](/documentation/TabularData/DiscontiguousColumnSlice) --- Copyright © 2026 Apple Inc. 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