Hashtable.Remove(Object) Method

public:
 virtual void Remove(System::Object ^ key);

public virtual void Remove(object key);

abstract member Remove : obj -> unit
override this.Remove : obj -> unit

Public Overridable Sub Remove (key As Object)

Parameters

Implements

Exceptions

Examples

The following example shows how to remove elements from 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("1a", "The");
 myHT.Add("1b", "quick");
 myHT.Add("1c", "brown");
 myHT.Add("2a", "fox");
 myHT.Add("2b", "jumps");
 myHT.Add("2c", "over");
 myHT.Add("3a", "the");
 myHT.Add("3b", "lazy");
 myHT.Add("3c", "dog");

 // Displays the Hashtable.
 Console.WriteLine("The Hashtable initially contains the following:");
 PrintKeysAndValues(myHT);

 // Removes the element with the key "3b".
 myHT.Remove("3b");

 // Displays the current state of the Hashtable.
 Console.WriteLine("After removing \"lazy\":");
 PrintKeysAndValues(myHT);
 }

 public static void PrintKeysAndValues(Hashtable myHT)
 {
 foreach (DictionaryEntry de in myHT)
 Console.WriteLine($" {de.Key}: {de.Value}");
 Console.WriteLine();
 }
}


/*
This code produces the following output.

The Hashtable initially contains the following:
 2c: over
 3a: the
 2b: jumps
 3b: lazy
 1b: quick
 3c: dog
 2a: fox
 1c: brown
 1a: The

After removing "lazy":
 2c: over
 3a: the
 2b: jumps
 1b: quick
 3c: dog
 2a: fox
 1c: brown
 1a: The

*/

Imports System.Collections

Public Class SamplesHashtable 
 
 Public Shared Sub Main()
 
 ' Creates and initializes a new Hashtable.
 Dim myHT As New Hashtable()
 myHT.Add("1a", "The")
 myHT.Add("1b", "quick")
 myHT.Add("1c", "brown")
 myHT.Add("2a", "fox")
 myHT.Add("2b", "jumps")
 myHT.Add("2c", "over")
 myHT.Add("3a", "the")
 myHT.Add("3b", "lazy")
 myHT.Add("3c", "dog")
 
 ' Displays the Hashtable.
 Console.WriteLine("The Hashtable initially contains the following:")
 PrintKeysAndValues(myHT)
 
 ' Removes the element with the key "3b".
 myHT.Remove("3b")
 
 ' Displays the current state of the Hashtable.
 Console.WriteLine("After removing ""lazy"":")
 PrintKeysAndValues(myHT)
 End Sub 
 
 
 Public Shared Sub PrintKeysAndValues(myHT As Hashtable)
 For Each de As DictionaryEntry In myHT
 Console.WriteLine($" {de.Key}: {de.Value}")
 Next
 Console.WriteLine()
 End Sub
End Class


' This code produces the following output.
' 
'The Hashtable initially contains the following:
' 1a: The
' 2c: over
' 3c: dog
' 1c: brown
' 2b: jumps
' 3b: lazy
' 1b: quick
' 2a: fox
' 3a: the

'After removing "lazy":
' 1a: The
' 2c: over
' 3c: dog
' 1c: brown
' 2b: jumps
' 1b: quick
' 2a: fox
' 3a: the

Remarks

If the Hashtable does not contain an element with the specified key, the Hashtable remains unchanged. No exception is thrown.

This method is an O(1) operation.

See also

• Add(Object, Object)
• Remove(Object)