hash_multimap::find
注意事項 |
---|
這個 API 已經過時。替代案例是 unordered_multimap 類別。 |
傳回位址的 Iterator 項目的第一個位置是一個索引鍵對應至指定索引鍵的 hash_multimap 的。
iterator find(
const Key& _Key
);
const_iterator find(
const Key& _Key
) const;
參數
- _Key
項目的排序鍵將符合索引鍵的項目從要搜尋的 hash_multimap 的。
傳回值
Iterator 處理一個項目的第一個集合中的特定索引鍵或成功最後一個項目的位置。hash_multimap,如果遊戲不為索引鍵中找到。
備註
說明 hash_multimap 的項目排序鍵是 equivalent 引數索引鍵在二進位述詞下會根據小於可比性關聯的定序的成員函式傳回 Iterator。
如果傳回值 find 給 const_iterator,無法修改 hash_multimap 物件。 如果的傳回值指派給 finditerator,可以修改 hash_multimap 物件。
在 Visual C++ .NET 2003 中, <hash_map> 和 <hash_set> 標頭檔的成員不在 std 命名空間中,而是移至 stdext 命名空間。 如需詳細資訊,請參閱 stdext 命名空間。
範例
// hash_multimap_find.cpp
// compile with: /EHsc
#include <iostream>
#include <hash_map>
int main()
{
using namespace std;
using namespace stdext;
hash_multimap<int, int> hm1;
hash_multimap<int, int> :: const_iterator hm1_AcIter, hm1_RcIter;
typedef pair<int, int> Int_Pair;
hm1.insert(Int_Pair(1, 10));
hm1.insert(Int_Pair(2, 20));
hm1.insert(Int_Pair(3, 20));
hm1.insert(Int_Pair(3, 30));
hm1_RcIter = hm1.find(2);
cout << "The element of hash_multimap hm1 with a key of 2 is: "
<< hm1_RcIter -> second << "." << endl;
hm1_RcIter = hm1.find(3);
cout << "The first element of hash_multimap hm1 with a key of 3 is: "
<< hm1_RcIter -> second << "." << endl;
// If no match is found for the key, end() is returned
hm1_RcIter = hm1.find(4);
if (hm1_RcIter == hm1.end())
cout << "The hash_multimap hm1 doesn't have an element "
<< "with a key of 4." << endl;
else
cout << "The element of hash_multimap hm1 with a key of 4 is: "
<< hm1_RcIter -> second << "." << endl;
// The element at a specific location in the hash_multimap can be
// found using a dereferenced iterator addressing the location
hm1_AcIter = hm1.end();
hm1_AcIter--;
hm1_RcIter = hm1.find(hm1_AcIter -> first);
cout << "The first element of hm1 with a key matching"
<< endl << "that of the last element is: "
<< hm1_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 (hm1_RcIter == --hm1.end())
cout << "This is the last element of hash_multimap hm1."
<< endl;
else
cout << "This is not the last element of hash_multimap hm1."
<< endl;
}
需求
標頭檔: <hash_map>
**命名空間:**stdext