Hashtable.Clear Method

public:
 virtual void Clear();

public virtual void Clear();

abstract member Clear : unit -> unit
override this.Clear : unit -> unit

Public Overridable Sub Clear ()

Implements

Exceptions

Examples

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.
 var myHT = new Hashtable();
 myHT.Add("one", "The");
 myHT.Add("two", "quick");
 myHT.Add("three", "brown");
 myHT.Add("four", "fox");
 myHT.Add("five", "jumps");

 // Displays the count and values of the Hashtable.
 Console.WriteLine("Initially,");
 Console.WriteLine($" Count : {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 : {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{de.Key}:\t{de.Value}");
 Console.WriteLine();
 }
}


/*
This code produces the following output.

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

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

*/

Imports System.Collections

Public Class SamplesHashtable

 Public Shared Sub Main()

 ' Creates and initializes a new Hashtable.
 Dim myHT As New Hashtable()
 myHT.Add("one", "The")
 myHT.Add("two", "quick")
 myHT.Add("three", "brown")
 myHT.Add("four", "fox")
 myHT.Add("five", "jumps")

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

 End Sub


 Public Shared Sub PrintKeysAndValues(myHT As Hashtable)
 Console.WriteLine(vbTab + "-KEY-" + vbTab + "-VALUE-")
 For Each de As DictionaryEntry In myHT
 Console.WriteLine(vbTab + "{0}:" + vbTab + "{1}", de.Key, de.Value)
 Next
 Console.WriteLine()
 End Sub

End Class


' This code produces the following output.
' 
' Initially,
' Count : 5
' Values:
' -KEY- -VALUE-
' two: quick
' five: jumps
' one: The
' three: brown
' four: fox
'
' After Clear,
' Count : 0
' Values:
' -KEY- -VALUE-
'

Remarks

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.

See also

• Clear()