vector::empty, vector::erase, 和 vector::push_back

在 Visual C++ 演示如何使用 向量:: null、 向量:: 清除和 向量:: push_back STL 功能。

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;

备注

备注

类/参数名在原型不匹配版本在头文件。修改某些提高可读性。

此示例声明整数一个空矢量。 它将 10 个整数为向量然后显示该个矢量的内容。 通过使用清除，它将删除第六个元素，然后再次显示了个矢量的内容。 删除该元素的其余部分使用 清除 的不同的窗体然后再次显示该矢量 (现在为空)。 ShowVector 实例是否使用 null 的功能确定生成一个矢量的内容。

示例

// 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 ;
}

要求

标题: vector

请参见

概念

标准模板库示例