StringCollection.Remove(String) Method

Reference

Definition

Namespace:: System.Collections.Specialized

Assemblies:: System.dll, System.Collections.Specialized.dll

Assemblies:: netstandard.dll, System.Collections.Specialized.dll

Assembly:: System.Collections.Specialized.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Source:: StringCollection.cs

Source:: StringCollection.cs

Source:: StringCollection.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Removes the first occurrence of a specific string from the StringCollection.

public:
 void Remove(System::String ^ value);

public void Remove(string value);

public void Remove(string? value);

member this.Remove : string -> unit

Public Sub Remove (value As String)

Parameters

value: String

The string to remove from the StringCollection. The value can be null.

Examples

The following code example removes elements from the StringCollection.

#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 );
   
   // Removes one element from the StringCollection.
   myCol->Remove( "yellow" );
   Console::WriteLine( "After removing \"yellow\":" );
   PrintValues( myCol );
   
   // Removes all occurrences of a value from the StringCollection.
   int i = myCol->IndexOf( "RED" );
   while ( i > -1 )
   {
      myCol->RemoveAt( i );
      i = myCol->IndexOf( "RED" );
   }

   Console::WriteLine( "After removing all occurrences of \"RED\":" );
   PrintValues( myCol );
   
   // Clears the entire collection.
   myCol->Clear();
   Console::WriteLine( "After clearing the collection:" );
   PrintValues( myCol );
}

void PrintValues( IEnumerable^ myCol )
{
   IEnumerator^ myEnum = myCol->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      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

After removing "yellow":
   RED
   orange
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After removing all occurrences of "RED":
   orange
   green
   blue
   indigo
   violet

After clearing the collection:

*/

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 );

      // Removes one element from the StringCollection.
      myCol.Remove( "yellow" );

      Console.WriteLine( "After removing \"yellow\":" );
      PrintValues( myCol );

      // Removes all occurrences of a value from the StringCollection.
      int i = myCol.IndexOf( "RED" );
      while ( i > -1 )  {
         myCol.RemoveAt( i );
         i = myCol.IndexOf( "RED" );
      }

      Console.WriteLine( "After removing all occurrences of \"RED\":" );
      PrintValues( myCol );

      // Clears the entire collection.
      myCol.Clear();

      Console.WriteLine( "After clearing the collection:" );
      PrintValues( myCol );
   }

   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

After removing "yellow":
   RED
   orange
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After removing all occurrences of "RED":
   orange
   green
   blue
   indigo
   violet

After clearing the collection:

*/

Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesStringCollection   

   Public Shared Sub Main()

      ' Creates and initializes a new StringCollection.
      Dim myCol As New StringCollection()
      Dim myArr() As [String] = {"RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED"}
      myCol.AddRange(myArr)

      Console.WriteLine("Initial contents of the StringCollection:")
      PrintValues(myCol)

      ' Removes one element from the StringCollection.
      myCol.Remove("yellow")

      Console.WriteLine("After removing ""yellow"":")
      PrintValues(myCol)

      ' Removes all occurrences of a value from the StringCollection.
      Dim i As Integer = myCol.IndexOf("RED")
      While i > - 1
         myCol.RemoveAt(i)
         i = myCol.IndexOf("RED")
      End While

      Console.WriteLine("After removing all occurrences of ""RED"":")
      PrintValues(myCol)

      ' Clears the entire collection.
      myCol.Clear()

      Console.WriteLine("After clearing the collection:")
      PrintValues(myCol)

   End Sub

   Public Shared Sub PrintValues(myCol As IEnumerable)
      Dim obj As [Object]
      For Each obj In  myCol
         Console.WriteLine("   {0}", obj)
      Next obj
      Console.WriteLine()
   End Sub

End Class


'This code produces the following output.
'
'Initial contents of the StringCollection:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'After removing "yellow":
'   RED
'   orange
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'After removing all occurrences of "RED":
'   orange
'   green
'   blue
'   indigo
'   violet
'
'After clearing the collection:
'

Remarks

Duplicate strings are allowed in StringCollection. Only the first occurrence is removed. To remove all occurrences of the specified string, use RemoveAt(IndexOf(value)) repeatedly while IndexOf does not return -1.

If the StringCollection does not contain the specified object, the StringCollection remains unchanged. No exception is thrown.

In collections of contiguous elements, such as lists, the elements that follow the removed element move up to occupy the vacated spot. If the collection is indexed, the indexes of the elements that are moved are also updated. This behavior does not apply to collections where elements are conceptually grouped into buckets, such as a hash table.

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.

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
.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

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