multimap::rbegin

傳回定址 Iterator 指向一項反向 multimap 的第一個項目。

const_reverse_iterator rbegin( ) const; 
reverse_iterator rbegin( );

傳回值

解決反向雙向 Iterator 的說明一項反向 multimap 的第一個項目或功能在 unreversed multimap 的最後一個項目。

備註

無效 啟動 搭配 multimap，rbegin 搭配一項反向 multimap。

如果 rbegin 的傳回值指派給 const_reverse_iterator，則無法修改 multimap 物件。 如果 rbegin 的傳回值指派給 reverse_iterator，則可以修改 multimap 物件。

rbegin 可用來逐一查看 multimap 向後逐一查看。

範例

// multimap_rbegin.cpp
// compile with: /EHsc
#include <map>
#include <iostream>

int main( )
{
   using namespace std;
   multimap <int, int> m1;

   multimap <int, int> :: iterator m1_Iter;
   multimap <int, int> :: reverse_iterator m1_rIter;
   multimap <int, int> :: const_reverse_iterator m1_crIter;
   typedef pair <int, int> Int_Pair;

   m1.insert ( Int_Pair ( 1, 10 ) );
   m1.insert ( Int_Pair ( 2, 20 ) );
   m1.insert ( Int_Pair ( 3, 30 ) );

   m1_rIter = m1.rbegin( );
   cout << "The first element of the reversed multimap m1 is "
        << m1_rIter -> first << "." << endl;

   // begin can be used to start an iteration 
   // throught a multimap in a forward order
   cout << "The multimap is: ";
   for ( m1_Iter = m1.begin( ) ; m1_Iter != m1.end( ); m1_Iter++)
      cout << m1_Iter -> first << " ";
      cout << "." << endl;

   // rbegin can be used to start an iteration 
   // throught a multimap in a reverse order
   cout << "The reversed multimap is: ";
   for ( m1_rIter = m1.rbegin( ) ; m1_rIter != m1.rend( ); m1_rIter++)
      cout << m1_rIter -> first << " ";
      cout << "." << endl;

   // A multimap element can be erased by dereferencing its key 
   m1_rIter = m1.rbegin( );
   m1.erase ( m1_rIter -> first );

   m1_rIter = m1.rbegin( );
   cout << "After the erasure, the first element "
        << "in the reversed multimap is "
        << m1_rIter -> first << "." << endl;
}

需求

標題: <map>

命名空間: std

請參閱

參考

multimap Class

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