在std :: map中查找不存在的键

#include<iostream>
#include <map>

int main() {
    std::map<int, std::string> my_map;
    my_map[1] = "one";
    my_map[2] = "two";
    my_map[3] = "three";

    int key_to_find = 4;
    auto it = my_map.find(key_to_find);

    if (it == my_map.end()) {
        std::cout << "Key "<< key_to_find << " not found in the map."<< std::endl;
    } else {
        std::cout << "Key "<< key_to_find << " found in the map with value: " << it->second<< std::endl;
    }

    return 0;
}