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Remove Method

Hashtable.Remove Method

Removes the element with the specified key from the Hashtable.

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

'Declaration
Public Overridable Sub Remove ( _
	key As Object _
)

Parameters

key
Type: System.Object

The key of the element to remove.

Implements

IDictionary.Remove(Object)

ExceptionCondition
ArgumentNullException

key is Nothing.

NotSupportedException

The Hashtable is read-only.

-or-

The Hashtable has a fixed size.

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.

The following example shows how to remove elements from the Hashtable.

Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

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", "jumped")
        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)
        Dim de As DictionaryEntry
        For Each de In  myHT
            Console.WriteLine("    {0}:    {1}", de.Key, de.Value)
        Next de
        Console.WriteLine()
    End Sub 
End Class 


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

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

.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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