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Hashtable.Clear Method

Removes all elements from the Hashtable.

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

public virtual void Clear()

Implements

IDictionary.Clear()

ExceptionCondition
NotSupportedException

The Hashtable is read-only.

Count is set to zero, and references to other objects from elements of the collection are also released. The capacity remains unchanged.

This method is an O(n) operation, where n is Count.

The following example shows how to clear the values of the Hashtable.

 using System;
 using System.Collections;
 public class SamplesHashtable  {

    public static void Main()  {

       // Creates and initializes a new Hashtable.
       Hashtable myHT = new Hashtable();
       myHT.Add( "one", "The" );
       myHT.Add( "two", "quick" );
       myHT.Add( "three", "brown" );
       myHT.Add( "four", "fox" );
       myHT.Add( "five", "jumped" );

       // Displays the count and values of the Hashtable.
       Console.WriteLine( "Initially," );
       Console.WriteLine( "   Count    : {0}", myHT.Count );
       Console.WriteLine( "   Values:" );
       PrintKeysAndValues( myHT );

       // Clears the Hashtable.
       myHT.Clear();

       // Displays the count and values of the Hashtable.
       Console.WriteLine( "After Clear," );
       Console.WriteLine( "   Count    : {0}", myHT.Count );
       Console.WriteLine( "   Values:" );
       PrintKeysAndValues( myHT );
    }


    public static void PrintKeysAndValues( Hashtable myHT )  {
       Console.WriteLine( "\t-KEY-\t-VALUE-" );
       foreach ( DictionaryEntry de in myHT )
          Console.WriteLine( "\t{0}:\t{1}", de.Key, de.Value );
       Console.WriteLine();
    }

 }


 /* 
 This code produces the following output.

 Initially,
    Count    : 5
    Values:
         -KEY-   -VALUE-
         two:    quick
         three:  brown
         four:   fox
         five:   jumped
         one:    The

 After Clear,
    Count    : 0
    Values:
         -KEY-   -VALUE-

 */

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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