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

Den Delimarsky|Last Updated: 8/18/2017
1 Contributor

Sorts the elements of an array, using the given projection for the keys and returning a new array. Elements are compared using

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

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


// Signature:
Array.sortBy : ('T -> 'Key) -> 'T [] -> 'T [] (requires comparison)

// Usage:
Array.sortBy projection array


projection Type: 'T -> 'Key

The function to transform array elements into the type that is compared.

array Type: 'T[]

The input array.

Return Value

The sorted array.


This is not a stable sort, that is, the original order of equal elements is not necessarily preserved. For a stable sort, consider using Seq.sort.

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.


The following code illustrates the use of Array.sortBy.

let sortedArray2 = Array.sortBy (fun elem -> abs elem) [|1; 4; 8; -2; 5|]
printfn "%A" sortedArray2


[|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.Array Module (F#)

Microsoft.FSharp.Collections Namespace (F#)

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