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StringCollection::Contains Method

Determines whether the specified string is in the StringCollection.

Namespace:  System.Collections.Specialized
Assembly:  System (in System.dll)

bool Contains(
	String^ value


Type: System::String

The string to locate in the StringCollection. The value can be nullptr.

Return Value

Type: System::Boolean
true if value is found in the StringCollection; otherwise, false.

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.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintValues( IEnumerable^ myCol );
int main()

   // Creates and initializes a new StringCollection.
   StringCollection^ myCol = gcnew StringCollection;
   array<String^>^myArr = {"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" ) );
      Console::WriteLine( "The collection does not contain \"orange\"." );

void PrintValues( IEnumerable^ myCol )
   IEnumerator^ myEnum = myCol->GetEnumerator();
   while ( myEnum->MoveNext() )
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   {0}", obj );


This code produces the following output.

Initial contents of the StringCollection:

The collection contains "orange" at index 1.


.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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