List.maxBy<'T,'U> Function (F#)

  • Article

Returns the greatest of all elements of the list, compared by using Operators.max on the function result.

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

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

// Signature:
List.maxBy : ('T -> 'U) -> 'T list -> 'T (requires comparison)

// Usage:
List.maxBy projection list

Parameters

  • projection
    Type: 'T -> 'U

    The function to transform the list elements into the type to be compared.

  • list
    Type: 'T list

    The input list.

Exceptions

Exception

Condition

ArgumentException

Thrown when the list is empty.

Return Value

The maximum element.

Remarks

This function is named MaxBy 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 List.maxBy.

[ -10.0 .. 10.0 ]
|> List.maxBy (fun x -> 1.0 - x * x)
|> printfn "%A"

Output

0.0

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

See Also

Reference

Collections.List Module (F#)

Microsoft.FSharp.Collections Namespace (F#)