map.find['key,'t]-function-[fsharp].md

title	Map.find<'Key,'T> Function (F#)
description	Map.find<'Key,'T> Function (F#)
keywords	visual f#, f#, functional programming
author	dend
manager	danielfe
ms.date	05/16/2016
ms.topic	language-reference
ms.prod	visual-studio-dev14
ms.technology	devlang-fsharp
ms.assetid	a3b17fac-ce16-4798-81f2-5f208723c22f

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

Looks up an element in the map. If no binding exists in the map, raises System.Collections.Generic.KeyNotFoundException.

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

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

Syntax

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

// Usage:
Map.find key table

Parameters

key Type: 'Key

The input key.

table Type: Map<'Key,'T>

The input map.

Exceptions

Exception	Condition
KeyNotFoundException	Thrown when the key does not exist in the map.

Return Value

The value mapped to the given key.

Remarks

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

Example

The following examples shows how to use Map.find.

[!code-fsharpMain]

Output

With key 1, found value "one".
With key 2, found value "two".
With key 3, found value 9.
With key 5, found value 25.
The given key was not present in the dictionary.

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.Map Module (F#)

Microsoft.FSharp.Collections Namespace (F#)