Hashtable::Remove Method (Object^)

 

Removes the element with the specified key from the Hashtable.

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

public:
virtual void Remove(
	Object^ key
)

Parameters

key
Type: System::Object^

The key of the element to remove.

Exception Condition
ArgumentNullException

key is null.

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.

using namespace System;
using namespace System::Collections;
void PrintKeysAndValues( Hashtable^ myHT );
int main()
{

   // Creates and initializes a new Hashtable.
   Hashtable^ myHT = gcnew 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 );
}

void PrintKeysAndValues( Hashtable^ myHT )
{
   IEnumerator^ myEnum = myHT->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      DictionaryEntry de = *safe_cast<DictionaryEntry ^>(myEnum->Current);
      Console::WriteLine( "    {0}:    {1}", de.Key, de.Value );
   }

   Console::WriteLine();
}

/*
 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

 */

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
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