我有這段代碼,我無法理解部分equal_range方法返回迭代器。 我知道的範圍是對與內部的兩個多重映射對象的對象,但我不明白,這就是爲什麼有'for (it = range.first; it != range.second; ++it)'
- 這是什麼意思是什麼呢?C++:STL multimap.equal_range()
// multmap.cpp -- use a multimap
#include <iostream>
#include <string>
#include <map>
#include <algorithm>
typedef int KeyType;
typedef std::pair<const KeyType, std::string> Pair;
typedef std::multimap<KeyType, std::string> MapCode;
int main()
{
using namespace std;
MapCode codes;
codes.insert(Pair(415, "San Francisco"));
codes.insert(Pair(510, "Oakland"));
codes.insert(Pair(718, "Brooklyn"));
codes.insert(Pair(718, "Staten Island"));
codes.insert(Pair(415, "San Rafael"));
codes.insert(Pair(510, "Berkeley"));
cout << "Number of cities with area code 415: "
<< codes.count(415) << endl;
cout << "Number of cities with area code 718: "
<< codes.count(718) << endl;
cout << "Number of cities with area code 510: "
<< codes.count(510) << endl;
cout << "Area Code City\n";
MapCode::iterator it;
for (it = codes.begin(); it != codes.end(); ++it)
cout << " " << (*it).first << " "
<< (*it).second << endl;
pair<MapCode::iterator, MapCode::iterator> range
= codes.equal_range(718);
cout << "Cities with area code 718:\n";
for (it = range.first; it != range.second; ++it) //<------------------ here
cout << (*it).second << endl;
return 0;
}
我認爲你的回答是最理解我,因爲它混淆了,看在迭代對象對成員。但是,如果它與* [container.begin(),container.end())'相同*沒關係。謝謝 – ashur