multimap::find

傳回處理一個項目的 Iterator 的位置在第一個有索引鍵等於指定的索引鍵 multimap 的。

iterator find(
   const Key& _Key
);
const_iterator find(
   const Key& _Key
) const;

參數

• _Key
  項目的排序鍵會符合的索引鍵會從所要搜尋之 multimap 的。

傳回值

處理一個項目的第一個位置具有指定索引鍵的 Iterator 成功或最後一個項目的位置在 multimap，如果符合沒有索引鍵中找到。

備註

成員函式來傳回處理已在 multimap 的項目排序鍵是 equivalent 引數對稱加密演算法中做為金鑰二進位述詞下比可比性關聯會根據的排程較少的 Iterator。

如果 find 的傳回值指派給 const_iterator，無法修改 multimap 物件。 如果 find 的傳回值指派給 iterator，可以修改 multimap 物件。

範例

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

int main( )
{
   using namespace std;
   multimap <int, int> m1;
   multimap <int, int> :: const_iterator m1_AcIter, m1_RcIter;
   typedef pair <int, int> Int_Pair;

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

   m1_RcIter = m1.find( 2 );
   cout << "The element of multimap m1 with a key of 2 is: "
        << m1_RcIter -> second << "." << endl;

   m1_RcIter = m1.find( 3 );
   cout << "The first element of multimap m1 with a key of 3 is: "
        << m1_RcIter -> second << "." << endl;

   // If no match is found for the key, end( ) is returned
   m1_RcIter = m1.find( 4 );

   if ( m1_RcIter == m1.end( ) )
      cout << "The multimap m1 doesn't have an element "
           << "with a key of 4." << endl;
   else
      cout << "The element of multimap m1 with a key of 4 is: "
           << m1_RcIter -> second << "." << endl;

   // The element at a specific location in the multimap can be
   // found using a dereferenced iterator addressing the location
   m1_AcIter = m1.end( );
   m1_AcIter--;
   m1_RcIter = m1.find( m1_AcIter -> first );
   cout << "The first element of m1 with a key matching"
        << endl << "that of the last element is: "
        << m1_RcIter -> second << "." << endl;

   // Note that the first element with a key equal to
   // the key of the last element is not the last element
   if ( m1_RcIter == --m1.end( ) )
      cout << "This is the last element of multimap m1."
           << endl;
   else
      cout << "This is not the last element of multimap m1."
           << endl;
}

需求

標題: <map>

命名空間: std

請參閱

參考

multimap Class

標準樣板程式庫