Map.map<'Key,'T,'U> Function (F#)
Creates a new collection whose elements are the results of applying the given function to each of the elements of the collection. The key passed to the function indicates the key of element being transformed.
Namespace/Module Path: Microsoft.FSharp.Collections.Map
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature:
Map.map : ('Key -> 'T -> 'U) -> Map<'Key,'T> -> Map<'Key,'U> (requires comparison)
// Usage:
Map.map mapping table
Parameters
mapping
Type: 'Key -> 'T -> 'UThe function to transform the key/value pairs.
table
Type: Map<'Key,'T>The input map.
Return Value
The resulting map of keys and transformed values.
Remarks
This function is named Map 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.map.
let map1 = Map.ofList [ (1, "One"); (2, "Two"); (3, "Three") ]
let map2 = map1 |> Map.map (fun key value -> value.ToUpper())
let map3 = map1 |> Map.map (fun key value -> value.ToLower())
printfn "%A" map1
printfn "%A" map2
printfn "%A" map3
Output
map [(1, "One"); (2, "Two"); (3, "Three")] map [(1, "ONE"); (2, "TWO"); (3, "THREE")] map [(1, "one"); (2, "two"); (3, "three")]
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