how to declare map values in c++ code example

Example 1: initialize map c++

std::map<std::string, int> mapOfMarks = {
		{"Riti",2},
		{"Jack",4}
};

Example 2: map in cpp

#include <map>

int main(){
  //new map
  std::map <int,int> myMap;
  myMap[0] = 1;
  myMap[1] = 2;
  myMap[2] = 3;
  myMap[3] = 4;
}