how to iterate in map c++ code example

Example 1: c++ map iterator

#include <iostream>
#include <map>
 
int main() {
  std::map<int, float> num_map;
  // calls a_map.begin() and a_map.end()
  for (auto it = num_map.begin(); it != num_map.end(); ++it) {
    std::cout << it->first << ", " << it->second << '\n';
  }
}

Example 2: cpp map iterate over keys

#include <iostream>
#include <map>

int main()
{
    std::map<std::string, int> myMap;

    myMap["one"] = 1;
    myMap["two"] = 2;
    myMap["three"] = 3;

    for ( const auto &myPair : myMap ) {
        std::cout << myPair.first << "\n";
    }
}