StringDictionary.Clear Method  
Definition
Important
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Removes all entries from the StringDictionary.
public:
 virtual void Clear();public virtual void Clear();abstract member Clear : unit -> unit
override this.Clear : unit -> unitPublic Overridable Sub Clear ()Exceptions
The StringDictionary is read-only.
Examples
The following code example demonstrates how to add and remove elements from a StringDictionary.
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesStringDictionary  {
   public static void Main()  {
      // Creates and initializes a new StringDictionary.
      StringDictionary myCol = new StringDictionary();
      myCol.Add( "red", "rojo" );
      myCol.Add( "green", "verde" );
      myCol.Add( "blue", "azul" );
      // Displays the values in the StringDictionary.
      Console.WriteLine( "Initial contents of the StringDictionary:" );
      PrintKeysAndValues( myCol );
      // Deletes an element.
      myCol.Remove( "green" );
      Console.WriteLine( "The collection contains the following elements after removing \"green\":" );
      PrintKeysAndValues( myCol );
      // Clears the entire collection.
      myCol.Clear();
      Console.WriteLine( "The collection contains the following elements after it is cleared:" );
      PrintKeysAndValues( myCol );
   }
   public static void PrintKeysAndValues( StringDictionary myCol )  {
      Console.WriteLine( "   KEY        VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-10} {1}", de.Key, de.Value );
      Console.WriteLine();
   }
}
/*
This code produces the following output.
Initial contents of the StringDictionary:
   KEY        VALUE
   green      verde
   red        rojo
   blue       azul
The collection contains the following elements after removing "green":
   KEY        VALUE
   red        rojo
   blue       azul
The collection contains the following elements after it is cleared:
   KEY        VALUE
*/
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesStringDictionary   
   Public Shared Sub Main()
      ' Creates and initializes a new StringDictionary.
      Dim myCol As New StringDictionary()
      myCol.Add("red", "rojo")
      myCol.Add("green", "verde")
      myCol.Add("blue", "azul")
      ' Displays the values in the StringDictionary.
      Console.WriteLine("Initial contents of the StringDictionary:")
      PrintKeysAndValues(myCol)
      ' Deletes an element.
      myCol.Remove("green")
      Console.WriteLine("The collection contains the following elements after removing ""green"":")
      PrintKeysAndValues(myCol)
      ' Clears the entire collection.
      myCol.Clear()
      Console.WriteLine("The collection contains the following elements after it is cleared:")
      PrintKeysAndValues(myCol)
   End Sub
   Public Shared Sub PrintKeysAndValues(myCol As StringDictionary)
      Dim de As DictionaryEntry
      Console.WriteLine("   KEY        VALUE")
      For Each de In  myCol
         Console.WriteLine("   {0,-10} {1}", de.Key, de.Value)
      Next de
      Console.WriteLine()
   End Sub
End Class
'This code produces the following output.
'
'Initial contents of the StringDictionary:
'   KEY        VALUE
'   green      verde
'   red        rojo
'   blue       azul
'
'The collection contains the following elements after removing "green":
'   KEY        VALUE
'   red        rojo
'   blue       azul
'
'The collection contains the following elements after it is cleared:
'   KEY        VALUE
'
Remarks
This method is an O(n) operation, where n is Count.