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Array.mapi2<'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, also passing the index of the elements. 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)

Syntax

// Signature:
Array.mapi2 : (int -> 'T1 -> 'T2 -> 'U) -> 'T1 [] -> 'T2 [] -> 'U []

// Usage:
Array.mapi2 mapping array1 array2

Parameters

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

The function to transform pairs of input elements and their indices.

array1 Type: 'T1[]

The first input array.

array2 Type: 'T2[]

The second input array.

Return Value

Returns the array of transformed elements.

Remarks

This function is named MapIndexed2 in compiled assemblies. If you are accessing the function from a language other than F#, or through reflection, use this name.

Example

The following code demonstrates the use of Array.mapi2.


    let array1 = [| 1; 2; 3 |]
    let array2 = [| 4; 5; 6 |]
    let arrayAddTimesIndex = Array.mapi2 (fun i x y -> (x + y) * i) array1 array2
    printfn "%A" arrayAddTimesIndex

Output

[|0; 7; 18|]

Platforms

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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