检查值存在于std :: map - C++中

#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 value_to_check = 2;
    if (my_map.find(value_to_check) != my_map.end()) {
        std::cout << "Value "<< value_to_check << " exists in the map."<< std::endl;
    } else {
        std::cout << "Value "<< value_to_check << " does not exist in the map."<< std::endl;
    }

    return 0;
}