• Article

List<T>.IList.IndexOf Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Determines the index of a specific item in the IList.

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

Syntax

'Declaration
Private Function IndexOf ( _
    item As Object _
) As Integer Implements IList.IndexOf

int IList.IndexOf(
    Object item
)

Parameters

Return Value

Type: System.Int32
The index of item if found in the list; otherwise, –1.

Implements

IList.IndexOf(Object)

Exceptions

Exception Condition
ArgumentException

item is of a type that is not assignable to the IList.

Remarks

This method determines equality using the default equality comparer EqualityComparer<T>.Default for T, the type of values in the list.

This method performs a linear search; therefore, this method is an O(n) operation, where n is Count.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.