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List(Of T).FindIndex Method (Int32, Predicate(Of T))

Searches for an element that matches the conditions defined by the specified predicate, and returns the zero-based index of the first occurrence within the range of elements in the List(Of T) that extends from the specified index to the last element.

Namespace:  System.Collections.Generic
Assembly:  mscorlib (in mscorlib.dll)

Public Function FindIndex ( _
	startIndex As Integer, _
	match As Predicate(Of T) _
) As Integer
Dim instance As List 
Dim startIndex As Integer 
Dim match As Predicate(Of T)
Dim returnValue As Integer 

returnValue = instance.FindIndex(startIndex, _


Type: System.Int32

The zero-based starting index of the search.

Type: System.Predicate(Of T)

The Predicate(Of T) delegate that defines the conditions of the element to search for.

Return Value

Type: System.Int32
The zero-based index of the first occurrence of an element that matches the conditions defined by match, if found; otherwise, –1.


match is Nothing.


startIndex is outside the range of valid indexes for the List(Of T).

The List(Of T) is searched forward starting at startIndex and ending at the last element.

The Predicate(Of T) is a delegate to a method that returns true if the object passed to it matches the conditions defined in the delegate. The elements of the current List(Of T) are individually passed to the Predicate(Of T) delegate.

This method performs a linear search; therefore, this method is an O(n) operation, where n is the number of elements from startIndex to the end of the List(Of T).

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0