std::map

 

#include <map>
#include <iostream>

using namespace std;

int main()
{
    std::map<int, std::string> _map = {
        {0, "00"},
        {1, "11"},
        {2, "22"}
    };

    // get value
    std::cout << _map[0] << std::endl;
    std::cout << _map[1] << std::endl;
    std::cout << _map[100] << std::endl;
    std::cout << _map.at(100) << std::endl;
    auto iter = _map.find(1);
    if (iter == _map.end()) {
        std::cout << "iter == _map.end()" << std::endl;
    } else {
        std::cout << "iter->second:" << iter->second << std::endl;
    }

    // insert value
    _map[100] = "boom";
    _map.insert(std::pair<int, std::string>(4, "44"));
    std::cout << _map[100] << std::endl;

    for (auto item = _map.begin(); item != _map.end(); item++)
    {
        std::cout << item->second << " ";
    }

    std::cout << endl;

    return 0;
}

muhe@muhe-HP:~/cm$ g++ -std=c++11 sd.c
muhe@muhe-HP:~/cm$ ./a.out
00
11

iter->second:11
boom
00 11 22 44 boom