Stack.Pop Metode

Definisi

Ruang nama:

System.Collections

Rakitan:

System.Collections.NonGeneric.dll

Sumber:

Stack.cs

Menghapus dan mengembalikan objek di bagian Stackatas .

public:
 virtual System::Object ^ Pop();

public virtual object? Pop ();

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

Public Overridable Function Pop () As Object

Mengembalikan

Object

dihapus Object dari bagian Stackatas .

Pengecualian

InvalidOperationException

Kosong Stack .

Contoh

Contoh berikut menunjukkan cara menambahkan elemen ke Stack, menghapus elemen dari Stack, atau melihat elemen di bagian Stackatas .

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

Keterangan

Metode ini mirip Peek dengan metode , tetapi Peek tidak memodifikasi Stack.

null dapat didorong ke Stack sebagai tempat penampung, jika diperlukan. Untuk membedakan antara nilai null dan akhir tumpukan, periksa Count properti atau tangkap InvalidOperationException, yang dilemparkan saat Stack kosong.

Metode ini adalah O(1) operasi.

Lihat juga

• Peek()
• Push(Object)