ArrayList.Add(Object) ArrayList.Add(Object) ArrayList.Add(Object) ArrayList.Add(Object) Method

Definizione

Aggiunge un oggetto alla fine di ArrayList.Adds an object to the end of the ArrayList.

public:
 virtual int Add(System::Object ^ value);
public virtual int Add (object value);
abstract member Add : obj -> int
override this.Add : obj -> int
Public Overridable Function Add (value As Object) As Integer

Parametri

value
Object Object Object Object

Object da aggiungere alla fine della classe ArrayList.The Object to be added to the end of the ArrayList. Il valore può essere null.The value can be null.

Restituisce

Indice ArrayList in corrispondenza del quale è stato aggiunto value.The ArrayList index at which the value has been added.

Implementazioni

Eccezioni

La classe ArrayList è di sola lettura.The ArrayList is read-only.

In alternativa-or- Le dimensioni dell'oggetto ArrayList sono fisse.The ArrayList has a fixed size.

Esempi

Esempio di codice seguente viene illustrato come aggiungere elementi al ArrayList.The following code example shows how to add elements to the ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList, char mySeparator );
int main()
{
   
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "The" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   
   // Creates and initializes a new Queue.
   Queue^ myQueue = gcnew Queue;
   myQueue->Enqueue( "jumps" );
   myQueue->Enqueue( "over" );
   myQueue->Enqueue( "the" );
   myQueue->Enqueue( "lazy" );
   myQueue->Enqueue( "dog" );
   
   // Displays the ArrayList and the Queue.
   Console::WriteLine( "The ArrayList initially contains the following:" );
   PrintValues( myAL, '\t' );
   Console::WriteLine( "The Queue initially contains the following:" );
   PrintValues( myQueue, '\t' );
   
   // Copies the Queue elements to the end of the ArrayList.
   myAL->AddRange( myQueue );
   
   // Displays the ArrayList.
   Console::WriteLine( "The ArrayList now contains the following:" );
   PrintValues( myAL, '\t' );
}

void PrintValues( IEnumerable^ myList, char mySeparator )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::Write( "{0}{1}", mySeparator, obj );
   }

   Console::WriteLine();
}

/* 
This code produces the following output.

The ArrayList initially contains the following:
    The    quick    brown    fox
The Queue initially contains the following:
    jumps    over    the    lazy    dog
The ArrayList now contains the following:
    The    quick    brown    fox    jumps    over    the    lazy    dog
*/
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );

      // Creates and initializes a new Queue.
      Queue myQueue = new Queue();
      myQueue.Enqueue( "jumps" );
      myQueue.Enqueue( "over" );
      myQueue.Enqueue( "the" );
      myQueue.Enqueue( "lazy" );
      myQueue.Enqueue( "dog" );

      // Displays the ArrayList and the Queue.
      Console.WriteLine( "The ArrayList initially contains the following:" );
      PrintValues( myAL, '\t' );
      Console.WriteLine( "The Queue initially contains the following:" );
      PrintValues( myQueue, '\t' );

      // Copies the Queue elements to the end of the ArrayList.
      myAL.AddRange( myQueue );

      // Displays the ArrayList.
      Console.WriteLine( "The ArrayList now contains the following:" );
      PrintValues( myAL, '\t' );
   }

   public static void PrintValues( IEnumerable myList, char mySeparator )  {
      foreach ( Object obj in myList )
         Console.Write( "{0}{1}", mySeparator, obj );
      Console.WriteLine();
   }

}


/* 
This code produces the following output.

The ArrayList initially contains the following:
    The    quick    brown    fox
The Queue initially contains the following:
    jumps    over    the    lazy    dog
The ArrayList now contains the following:
    The    quick    brown    fox    jumps    over    the    lazy    dog
*/ 
Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

Public Class SamplesArrayList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        
        ' Creates and initializes a new Queue.
        Dim myQueue As New Queue()
        myQueue.Enqueue("jumps")
        myQueue.Enqueue("over")
        myQueue.Enqueue("the")
        myQueue.Enqueue("lazy")
        myQueue.Enqueue("dog")
        
        ' Displays the ArrayList and the Queue.
        Console.WriteLine("The ArrayList initially contains the following:")
        PrintValues(myAL, ControlChars.Tab)
        Console.WriteLine("The Queue initially contains the following:")
        PrintValues(myQueue, ControlChars.Tab)
        
        ' Copies the Queue elements to the end of the ArrayList.
        myAL.AddRange(myQueue)
        
        ' Displays the ArrayList.
        Console.WriteLine("The ArrayList now contains the following:")
        PrintValues(myAL, ControlChars.Tab)
    End Sub

    Public Shared Sub PrintValues(myList As IEnumerable, mySeparator As Char)
        Dim obj As [Object]
        For Each obj In  myList
          Console.Write( "{0}{1}", mySeparator, obj )
        Next obj
        Console.WriteLine()
    End Sub 'PrintValues

End Class


' This code produces the following output.
' 
' The ArrayList initially contains the following:
'     The    quick    brown    fox
' The Queue initially contains the following:
'     jumps    over    the    lazy    dog
' The ArrayList now contains the following:
'     The    quick    brown    fox    jumps    over    the    lazy    dog 

Commenti

ArrayList accetta null come un valore valido e consente gli elementi duplicati.ArrayList accepts null as a valid value and allows duplicate elements.

Se Count è già pari Capacity, la capacità del ArrayList viene incrementato automaticamente la riallocazione della matrice interna, e vengono copiati gli elementi esistenti nella nuova matrice prima che venga aggiunto il nuovo elemento.If Count already equals Capacity, the capacity of the ArrayList is increased by automatically reallocating the internal array, and the existing elements are copied to the new array before the new element is added.

Se Count è minore di Capacity, questo metodo è un'operazione o (1).If Count is less than Capacity, this method is an O(1) operation. Se la capacità deve essere incrementata per far posto al nuovo elemento, questo metodo diventa un'operazione O (n) operazione, in cui n è Count.If the capacity needs to be increased to accommodate the new element, this method becomes an O(n) operation, where n is Count.

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