how to iterate over a map cpp code example

Example 1: through map c++

//Since c++17
for (auto& [key, value]: myMap) {
    cout << key << " has value " << value << endl;
}
//Since c++11
for (auto& kv : myMap) {
    cout << kv.first << " has value " << kv.second << endl;
}

Example 2: cpp goiver all the map values

map<string, int>::iterator it;

for (it = symbolTable.begin(); it != symbolTable.end(); it++)
{
    std::cout << it->first    // string (key)
              << ':'
              << it->second   // string's value 
              << std::endl;
}

Example 3: 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";
    }
}