Map.tryFind<'Key,'T> Function (F#)

Artikel
02/04/2013

Looks up an element in the map, returning a Some value if the element is in the domain of the map and None if not.

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

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

// Signature:
Map.tryFind : 'Key -> Map<'Key,'T> -> 'T option (requires comparison)

// Usage:
Map.tryFind key table

Parameters

key
Type: 'Key

The input key.
table
Type: Map<'Key,'T>

The input map.

Return Value

The found Some value or None.

Remarks

This function is named TryFind 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 shows how to use Map.tryFind.

let map1 = [ for i in 1 .. 100 -> (i, i*i) ] |> Map.ofList
let result = Map.tryFind 50 map1
match result with
| Some x -> printfn "Found %d." x
| None -> printfn "Did not find the specified value."

Output

Found 2500.

Platforms

Windows 7, Windows Vista SP2, Windows XP SP3, Windows XP x64 SP2, Windows Server 2008 R2, Windows Server 2008 SP2, Windows Server 2003 SP2

Version Information

F# Runtime

Supported in: 2.0, 4.0

Silverlight

Supported in: 3

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