Stack.Push(Object) Método

Definición

Espacio de nombres:

System.Collections

Ensamblado:

System.Collections.NonGeneric.dll

Source:

Stack.cs

Inserta un objeto al principio de Stack.

public:
 virtual void Push(System::Object ^ obj);

public virtual void Push (object? obj);

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

Public Overridable Sub Push (obj As Object)

Parámetros

obj

Object

Object a insertar en la Stack. El valor puede ser null.

Ejemplos

En el ejemplo siguiente se muestra cómo agregar elementos a Stack, quitar elementos de Stacko ver el elemento en la parte superior de Stack.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myCollection, char mySeparator );
int main()
{
   
   // Creates and initializes a new Stack.
   Stack^ myStack = gcnew Stack;
   myStack->Push( "The" );
   myStack->Push( "quick" );
   myStack->Push( "brown" );
   myStack->Push( "fox" );
   
   // Displays the Stack.
   Console::Write( "Stack values:" );
   PrintValues( myStack, '\t' );
   
   // Removes an element from the Stack.
   Console::WriteLine( "(Pop)\t\t{0}", myStack->Pop() );
   
   // Displays the Stack.
   Console::Write( "Stack values:" );
   PrintValues( myStack, '\t' );
   
   // Removes another element from the Stack.
   Console::WriteLine( "(Pop)\t\t{0}", myStack->Pop() );
   
   // Displays the Stack.
   Console::Write( "Stack values:" );
   PrintValues( myStack, '\t' );
   
   // Views the first element in the Stack but does not remove it.
   Console::WriteLine( "(Peek)\t\t{0}", myStack->Peek() );
   
   // Displays the Stack.
   Console::Write( "Stack values:" );
   PrintValues( myStack, '\t' );
}

void PrintValues( IEnumerable^ myCollection, char mySeparator )
{
   IEnumerator^ myEnum = myCollection->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.
 
 Stack values:    fox    brown    quick    The
 (Pop)        fox
 Stack values:    brown    quick    The
 (Pop)        brown
 Stack values:    quick    The
 (Peek)        quick
 Stack values:    quick    The
 */

using System;
using System.Collections;
public class SamplesStack  {

   public static void Main()  {

      // Creates and initializes a new Stack.
      Stack myStack = new Stack();
      myStack.Push( "The" );
      myStack.Push( "quick" );
      myStack.Push( "brown" );
      myStack.Push( "fox" );

      // Displays the Stack.
      Console.Write( "Stack values:" );
      PrintValues( myStack, '\t' );

      // Removes an element from the Stack.
      Console.WriteLine( "(Pop)\t\t{0}", myStack.Pop() );

      // Displays the Stack.
      Console.Write( "Stack values:" );
      PrintValues( myStack, '\t' );

      // Removes another element from the Stack.
      Console.WriteLine( "(Pop)\t\t{0}", myStack.Pop() );

      // Displays the Stack.
      Console.Write( "Stack values:" );
      PrintValues( myStack, '\t' );

      // Views the first element in the Stack but does not remove it.
      Console.WriteLine( "(Peek)\t\t{0}", myStack.Peek() );

      // Displays the Stack.
      Console.Write( "Stack values:" );
      PrintValues( myStack, '\t' );
   }

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


/*
This code produces the following output.

Stack values:    fox    brown    quick    The
(Pop)        fox
Stack values:    brown    quick    The
(Pop)        brown
Stack values:    quick    The
(Peek)        quick
Stack values:    quick    The
*/

Imports System.Collections

Public Class SamplesStack    

    Public Shared Sub Main()

        ' Creates and initializes a new Stack.
        Dim myStack As New Stack()
        myStack.Push("The")
        myStack.Push("quick")
        myStack.Push("brown")
        myStack.Push("fox")

        ' Displays the Stack.
        Console.Write("Stack values:")
        PrintValues(myStack, ControlChars.Tab)

        ' Removes an element from the Stack.
        Console.WriteLine("(Pop)" & ControlChars.Tab & ControlChars.Tab & _
           "{0}", myStack.Pop())

        ' Displays the Stack.
        Console.Write("Stack values:")
        PrintValues(myStack, ControlChars.Tab)

        ' Removes another element from the Stack.
        Console.WriteLine("(Pop)" & ControlChars.Tab & ControlChars.Tab & _
           "{0}", myStack.Pop())

        ' Displays the Stack.
        Console.Write("Stack values:")
        PrintValues(myStack, ControlChars.Tab)

        ' Views the first element in the Stack but does not remove it.
        Console.WriteLine("(Peek)" & ControlChars.Tab & ControlChars.Tab & _
           "{0}", myStack.Peek())

        ' Displays the Stack.
        Console.Write("Stack values:")
        PrintValues(myStack, ControlChars.Tab)

    End Sub

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

End Class


' This code produces the following output.
' 
' Stack values:    fox    brown    quick    The
' (Pop)        fox
' Stack values:    brown    quick    The
' (Pop)        brown
' Stack values:    quick    The
' (Peek)        quick
' Stack values:    quick    The

Comentarios

Si Count ya es igual a la capacidad, la capacidad de se incrementa mediante la reasignación automática de Stack la matriz interna y los elementos existentes se copian en la nueva matriz antes de agregar el nuevo elemento.

null se puede insertar en Stack como marcador de posición, si es necesario. Ocupa una ranura en la pila y se trata como cualquier objeto.

Si Count es menor que la capacidad de la pila, Push es una O(1) operación. Si es necesario aumentar la capacidad para acomodar el nuevo elemento, Push se convierte en una O(n) operación, donde n es Count.

Consulte también

• Peek()
• Pop()