map::upper_bound

傳回 Iterator 置於與現有索引鍵值大於指定的索引鍵對應的第一個項目。

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

參數

• _Key
  引數索引鍵值與項目比較的排序鍵值從搜尋的對應。

傳回值

處理一個項目位置對應中的索引鍵大於引數金鑰，或是處理成功最後一個項目的位置對應中的 iterator 則為 const_iterator ，如果遊戲不為索引鍵中找到。

如果的傳回值指派給 const_iterator，無法修改對應物件。 如果的傳回值指派給 iterator，可以修改對應物件。

範例

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

int main( )
{
   using namespace std;
   map <int, int> m1;
   map <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, 30 ) );

   m1_RcIter = m1.upper_bound( 2 );
   cout << "The first element of map m1 with a key "
        << "greater than 2 is: "
        << m1_RcIter -> second << "." << endl;

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

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

   // The element at a specific location in the map can be found 
   // using a dereferenced iterator addressing the location
   m1_AcIter = m1.begin( );
   m1_RcIter = m1. upper_bound ( m1_AcIter -> first );
   cout << "The 1st element of m1 with a key greater than\n"
        << "that of the initial element of m1 is: "
        << m1_RcIter -> second << "." << endl;
}

需求

標頭：<map>

命名空間: std

請參閱

參考

map 類別

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