ExtraTopLevelOperators.eprintf<'T> Function (F#)

Print to stderr using the given format.

Namespace/Module Path: Microsoft.FSharp.Core.ExtraTopLevelOperators

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

// Signature:
eprintf : TextWriterFormat<'T> -> 'T

// Usage:
eprintf format

Parameters

• format
  Type: TextWriterFormat<'T>

Remarks

This function is named PrintFormatToError 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 example demonstrates the use of eprintf.

let maxValue = 10
let function1 x =
   if (x > maxValue) then
       eprintf "Error: the input %d exceeds the maximum value, %d." x maxValue
   else
       printfn "Success!"
function1 1
function1 11
// Issue a newline to stderr to trigger printing.
stderr.WriteLine()

The output is as follows.

Success!
Error: the input 11 exceeds the maximum value 10.

Platforms

Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2

Version Information

F# Core Library Versions

Supported in: 2.0, 4.0

See Also

Reference

Core.ExtraTopLevelOperators Module (F#)

Microsoft.FSharp.Core Namespace (F#)