vector::empty, vector::erase, und vector::push_back

Veranschaulicht, wie die Vektor::leer, Vektor::Löschenund Vektor::push_back STL Features von Visual C++ verwendet.

template<class _TYPE, class _A>
   void vector::push_back( 
      const _TYPE& X  
   );
template<class _TYPE, class _A>
   iterator vector::erase( 
      iterator Iterator  
   );
template<class _TYPE, class _A>
   iterator vector::erase( 
      iterator First,  
      iterator Last  
   );
template<class _TYPE, class _A>
    bool vector::empty( ) const;

Hinweise

Hinweis
Die Klasse/Parameternamen im Prototyp stimmen nicht mit der Version in der Headerdatei ab.Einige wurden geändert, um die Lesbarkeit zu verbessern.

Das Beispiel deklariert einen leeren Vektor von ganzen Zahlen.Es fügt 10 ganze Zahlen dem Vektor hinzu und zeigt anschließend den Inhalt des Vektors.Es wird also 6. - Element, indem Löschen verwendet, und zeigt anschließend den Inhalt des Vektors erneut.Für den Rest der Elemente mithilfe eines anderen Form von erase und zeigt dann den Vektor (leeren), werden Sie jetzt erneut auf.Die ShowVector-routinemäßigen Einsätze die leere Funktion, um zu bestimmen, ob der Inhalt dieses Vektors generiert.

Beispiel

// Empty.cpp
// compile with: /EHsc
// Illustrates the vector::empty and vector::erase functions.
// Also demonstrates the vector::push_back function.
//
// Functions:
//
//    vector::empty - Returns true if vector has no elements.
//
//    vector::erase - Deletes elements from a vector (single & range).
//
//    vector::begin - Returns an iterator to start traversal of the
//                    vector.
//
//    vector::end - Returns an iterator for the last element of the
//                  vector.
//
//    vector::push_back - Appends (inserts) an element to the end of a
//                        vector, allocating memory for it if necessary.
//
//    vector::iterator - Traverses the vector.
//
//////////////////////////////////////////////////////////////////////

// The debugger can't handle symbols more than 255 characters long.
// STL often creates symbols longer than that.
// When symbols are longer than 255 characters, the warning is disabled.
#pragma warning(disable:4786)

#include <iostream>
#include <vector>

using namespace std ;

typedef vector<int> INTVECTOR;

const int ARRAY_SIZE = 10;

void ShowVector(INTVECTOR &theVector);

int main()
{
    // Dynamically allocated vector begins with 0 elements.
    INTVECTOR theVector;

    // Intialize the vector to contain the numbers 0-9.
    for (int cEachItem = 0; cEachItem < ARRAY_SIZE; cEachItem++)
        theVector.push_back(cEachItem);

    // Output the contents of the dynamic vector of integers.
    ShowVector(theVector);

    // Using void iterator erase(iterator Iterator) to
    // delete the 6th element (Index starts with 0).
    theVector.erase(theVector.begin() + 5);

    // Output the contents of the dynamic vector of integers.
    ShowVector(theVector);

    // Using iterator erase(iterator First, iterator Last) to
    // delete a range of elements all at once.
    theVector.erase(theVector.begin(), theVector.end());

    // Show what's left (actually, nothing).
    ShowVector(theVector);
}

// Output the contents of the dynamic vector or display a
// message if the vector is empty.
void ShowVector(INTVECTOR &theVector)
{
    // First see if there's anything in the vector. Quit if so.
    if (theVector.empty())
    {
        cout << "theVector is empty." << endl;
        return;
    }

    // Iterator is used to loop through the vector.
    INTVECTOR::iterator theIterator;

    // Output contents of theVector.
    cout << "theVector [ " ;
    for (theIterator = theVector.begin(); theIterator != theVector.end();
         theIterator++)
    {
        cout << *theIterator;
        if (theIterator != theVector.end()-1) cout << ", ";
                                              // cosmetics for the output
    }
    cout << " ]" << endl ;
}

Anforderungen

Header: <vector>

Siehe auch

Konzepte

Standardvorlagenbibliotheks-Beispiele