Array.pick<'T,'U> Function (F#)

Articolo
04/28/2015

Applies the given function to successive elements, returning the first result where function returns Some. If the function never returns Some then KeyNotFoundException is raised.

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

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

// Signature:
Array.pick : ('T -> 'U option) -> 'T [] -> 'U

// Usage:
Array.pick chooser array

Parameters

chooser
Type: 'T -> 'Uoption

The function to generate options from the elements.
array
Type: 'T[]

The input array.

Exceptions

Exception	Condition
KeyNotFoundException	Thrown if every result from chooser is None.

Return Value

The first result.

Remarks

This function is named Pick 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 example shows how to use Array.pick.

let values = [| ("a", 1); ("b", 2); ("c", 3) |]

let resultPick = Array.pick (fun elem ->
                    match elem with
                    | (value, 2) -> Some value
                    | _ -> None) values
printfn "%A" resultPick

Output

"b"

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

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