StringCollection.Contains Method (String)
Determines whether the specified string is in the StringCollection.
Assembly: System (in System.dll)
Parameters
- value
-
Type:
System.String
The string to locate in the StringCollection. The value can be null.
The Contains method can confirm the existence of a string before performing further operations.
This method determines equality by calling Object.Equals. String comparisons are case-sensitive.
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.
The following code example searches the StringCollection for an element.
using System; using System.Collections; using System.Collections.Specialized; public class SamplesStringCollection { public static void Main() { // Creates and initializes a new StringCollection. StringCollection myCol = new StringCollection(); String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" }; myCol.AddRange( myArr ); Console.WriteLine( "Initial contents of the StringCollection:" ); PrintValues( myCol ); // Checks whether the collection contains "orange" and, if so, displays its index. if ( myCol.Contains( "orange" ) ) Console.WriteLine( "The collection contains \"orange\" at index {0}.", myCol.IndexOf( "orange" ) ); else Console.WriteLine( "The collection does not contain \"orange\"." ); } public static void PrintValues( IEnumerable myCol ) { foreach ( Object obj in myCol ) Console.WriteLine( " {0}", obj ); Console.WriteLine(); } } /* This code produces the following output. Initial contents of the StringCollection: RED orange yellow RED green blue RED indigo violet RED The collection contains "orange" at index 1. */
Available since 10
.NET Framework
Available since 1.1