map at function c++
// map::at
#include <iostream>
#include <string>
#include <map>
int main ()
{
std::map<std::string,int> mymap = {
{ "alpha", 0 },
{ "beta", 0 },
{ "gamma", 0 } };
mymap.at("alpha") = 10;
mymap.at("beta") = 20;
mymap.at("gamma") = 30;
for (auto& x: mymap) {
std::cout << x.first << ": " << x.second << '\n';
}
return 0;
}