#include <map>
// ===== CONSTRUCTOR
// map (char -> int)
std::map<char,int> map_int;
map_int['a']=10;
map_int['b']=30;
// map (int -> string)
std::map<int, std::string> map_string;
map_string[24] = "46";
// ===== EXISTENCE and SIZE
// map size
map_int.size() : size_type (int)
// search for 'a'
// map.find(key) : map.iterator
if(map_int.find('a') != map_int.end()) {/*...*/}
// map_iterator->first : type(key)
// map_iterator->second : type(value)
// check if the map is empty
map_int.empty() // : bool
// ===== SET
// just name and set
// if the element already exists, the statement will override that value
map_int['a']=10;
// check before set
if(map_int.find('a') == map_int.end())
map_int['a']=10;
// ===== DELETE
// first: iterator, then: erase(it)
auto it = map_int.find('a');
if(it != map_int.end())
map_int.erase(it);
// or also, using keys
map_int.erase('a');