Seq.tryFindIndex<'T> Function (F#)

Attempts to find the first element that satisfies a given predicate, and returns the index of the matching element.

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

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

// Signature:
Seq.tryFindIndex : ('T -> bool) -> seq<'T> -> int option

// Usage:
Seq.tryFindIndex predicate source

Parameters

• predicate
  Type: 'T ->bool

  A function that evaluates to a Boolean when given an item in the sequence.

• source
  Type: seq<'T>

  The input sequence.

Exceptions

Exception	Condition
ArgumentNullException	Thrown when the input sequence is null.

Return Value

Returns the index of the first element in the sequence that satisfies the given predicate, or None if no such element exists.

Remarks

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

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

Reference

Collections.Seq Module (F#)

Microsoft.FSharp.Collections Namespace (F#)