multimap::find

返回解决的迭代器一个元素的第一个位置在具有键等效于指定的键的基于的。

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

参数

• _Key
  一个元素的排序关键字将匹配的键从要搜索的基于的。

返回值

解决一个元素第一个位置与指定的键的迭代器或成功最后一个元素的位置在基于匹配项，则也没有为键中。

备注

成员函数返回解决在基于的元素排序关键字是 等效 给参数键在二进制谓词该应用可比性关系生成基于的排序小于零的迭代器。

如果 find 的返回值赋给 const_iterator，不能修改基于对象。如果 find 的返回值赋给 iterator，可以修改基于对象。

示例

// 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;
}

要求

标头: <map>

命名空间: std

请参见

参考

multimap Class

标准模板库