StringCollection.IList.IndexOf(Object) Method

Definition

Searches for the specified Object and returns the zero-based index of the first occurrence within the entire StringCollection.

C#
int IList.IndexOf(object value);
C#
int IList.IndexOf(object? value);

Parameters

value
Object

The Object to locate in the StringCollection. The value can be null.

Returns

The zero-based index of the first occurrence of value within the entire StringCollection, if found; otherwise, -1.

Implements

Remarks

The StringCollection is searched forward starting at the first element and ending at the last element.

This method determines equality by calling Object.Equals.

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

Starting with the .NET Framework 2.0, this method uses the collection's objects' Equals and CompareTo methods on item to determine whether item exists. In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1
UWP 10.0

See also