main() {

  // one way of adding elements
  Map has = new Map();
  has['key1'] = '1';
  has['key3'] = 23;

  print(has);

  //another way of adding elements
  Map m = {'1': 1, '2':2};
  print(m);

  //printing using for each
  m.forEach((key, value) => print('$key and $value'));

  //removing elements
  m.remove('2');
  print(m);

}