Hashtable.Remove(Object) Método

Definição

Namespace:
System.Collections
Assemblies:
mscorlib.dll, System.Collections.NonGeneric.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Remove o elemento com a chave especificada do Hashtable.

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)

Parâmetros

key
Object

A chave do elemento a ser removido.

Implementações

Remove(Object)

Exceções

ArgumentNullException

key é null.

NotSupportedException

O Hashtable é somente leitura.

-ou-

O Hashtable tem um tamanho fixo.

Exemplos

O exemplo a seguir mostra como remover elementos do 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

Comentários

Se o Hashtable elemento não contiver um elemento com a chave especificada, ele Hashtable permanecerá inalterado. Nenhuma exceção é gerada.

Esse método é uma O(1) operação.

Aplica-se a

Confira também