List<T>.IList.IndexOf(Object) Method

Reference

Definition

Namespace:: System.Collections.Generic

Assembly:: System.Collections.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: List.cs

Source:: List.cs

Source:: List.cs

Important

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Determines the index of a specific item in the IList.

 virtual int System.Collections.IList.IndexOf(System::Object ^ item) = System::Collections::IList::IndexOf;

int IList.IndexOf (object item);

abstract member System.Collections.IList.IndexOf : obj -> int
override this.System.Collections.IList.IndexOf : obj -> int

Function IndexOf (item As Object) As Integer Implements IList.IndexOf

Parameters

item: Object

The object to locate in the IList.

Returns

Int32

The index of item if found in the list; otherwise, -1.

Implements

IndexOf(Object)

Exceptions

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.

Applies to

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