编辑代码

void main() {
  
  var map = {};


  map.addEntries({"age": "18", "gender": "男"}.entries);
  print(map);

map.addAll({"age": "22"});
  print(map);
  map.values.join(',   ');
    print(map);
    
    print(map.entries.singleWhere(
         (e) => e.value == '22'
    ).key);


}