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List.sortBy<'T,'Key> Function (F#)

Den Delimarsky|Last Updated: 7/6/2016
1 Contributor

Sorts the given list using keys given by the given projection. Keys are compared using

Namespace/Module Path: Microsoft.FSharp.Collections.List

Assembly: FSharp.Core (in FSharp.Core.dll)


// Signature:
List.sortBy : ('T -> 'Key) -> 'T list -> 'T list (requires comparison)

// Usage:
List.sortBy projection list


projection Type: 'T -> 'Key

The function to transform the list elements into the type to be compared.

list Type: 'Tlist

The input list.

Return Value

The sorted list.


This is a stable sort, that is, the original order of equal elements is preserved.

This function is named SortBy in compiled assemblies. If you are accessing the function from a language other than F#, or through reflection, use this name.


let sortedList2 = List.sortBy (fun elem -> abs elem) [1; 4; 8; -2; 5]
printfn "%A" sortedList2


[1; -2; 4; 5; 8]


Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2

Version Information

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

See Also

Collections.List Module (F#)

Microsoft.FSharp.Collections Namespace (F#)

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