C++ 标准模板库（STL）——迭代器（iterators）的用法及理解

#include<iostream>
#include<set>        
using namespace std;

int main()
{
    set<int> int_set;
    for (int i = 0; i < 5; i++)
    {
        int_set.insert(i);            
    }
    for (auto start = int_set.begin(); start != int_set.end(); start++)
    {                       
        cout << *start << endl;
    }return 0;
}

#include<iostream>
#include<map>    
using namespace std;

int main()
{
    map<int, char> my_map;                                 
    my_map[0] = ‘a‘;                                        
    my_map[1] = ‘b‘;
    my_map.insert(map<int, char>::value_type(2, ‘c‘));       
    for (auto it = my_map.begin(); it != my_map.end(); it++) //map.begin()、map.end()：返回map的首、尾迭代器
    {
        cout << "key: " << it->first << " value: " << it->second << endl;
    }return 0;
}