stl map c++ code example

Example 1: map declaration c++

//assuming your variables are called : variables_
#include <map>
#include <string>

std::map<int, std::string> map_;
map_[1] = "mercury";
map_[2] = "mars";
map_.insert(std::make_pair(3, "earth"));
//either synthax works to declare a new entry

return map_[2]; //here, map_[2] will return "mars"

Example 2: map c++

#include <iostream>
#include <string>
#include <map>

using std::string;
using std::map;

int main() {
	// A new map
  	map<string, int> myMap = { // This equals sign is optional
		{"one", 1},
    	{"two", 2},
    	{"three", 3}
  	};

  	// Print map contents with a range-based for loop
    // (works in C++11 or higher)
  	for (auto& iter: myMap) {
    	std::cout << iter.first << ": " << iter.second << std::endl;  
  	}
}

Example 3: 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;
}