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

项目
04/28/2015

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 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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