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Array.map2<'T1,'T2,'U> Function (F#)

Den Delimarsky|Last Updated: 6/8/2016
1 Contributor

Builds a new collection whose elements are the results of applying the given function to the corresponding elements of the two collections pairwise. The two input arrays must have the same lengths, otherwise ArgumentException is raised.

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

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


// Signature:
Array.map2 : ('T1 -> 'T2 -> 'U) -> 'T1 [] -> 'T2 [] -> 'U []

// Usage:
Array.map2 mapping array1 array2


mapping Type: 'T1 -> 'T2 -> 'U

The function to transform the pairs of the input elements.

array1 Type: 'T1[]

The first input array.

array2 Type: 'T2[]

The second input array.

Return Value

Returns the array of transformed elements.


This function is named Map2 in compiled assemblies. If you are accessing the function from a .NET language other than F#, or through reflection, use this name.


The following code example shows the use of Array.map2.

    let array1 = [| 1; 2; 3 |]
    let array2 = [| 4; 5; 6 |]
    let arrayOfSums = Array.map2 (fun x y -> x + y) array1 array2
    printfn "%A" arrayOfSums


[|5; 7; 9|]


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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