Array.mapi<'T,'U> Function (F#)
Builds a new array whose elements are the results of applying the given function to each of the elements of the array. The integer index passed to the function indicates the index of element being transformed.
Namespace/Module Path: Microsoft.FSharp.Collections.Array
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature:
Array.mapi : (int -> 'T -> 'U) -> 'T [] -> 'U []
// Usage:
Array.mapi mapping array
Parameters
mapping
Type: int -> 'T -> 'UThe function to transform elements and their indices.
array
Type: 'T[]The input array.
Return Value
The array of transformed elements.
Remarks
This function is named MapIndexed 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.mapi.
let array1 = [| 1; 2; 3 |]
let newArray = Array.mapi (fun i x -> (i, x)) array1
printfn "%A" newArray
Output
[|(0, 1); (1, 2); (2, 3)|]
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