Map In Dart

Map In Flutter:

Map in dart

Map
- Map is collection of key/value pairs. You can retrieve or iterator a value and key. 
- Map instance with the default implementation, [LinkedHashMap].
  var mapData = new Map();
  mapData['username'] = 'admin';
  mapData['password'] = 'admin';
  print(mapData);

Which is use
- HashMap -  unordered (no order is guaranteed). HashMap<String, String> oo = new HashMap<String, String>();
- LinkedHashMap - key insertion order
- sorted map - keys in sorted order
- SplayTreeMap - selef - balancing binary tree. Allow recently accessed elements to be fast.  

LinkedHashMap
- It allows `null` as a key.

Iterat / get data (flutter how to get data Map or HashMap)
HashMap<String, String> hashMapFlutter = new HashMap<String, String>();
hashMapFlutter.forEach((k,v) => print(k));