code tweaks suggested by thso

Author: kwalrath

public/docs/_examples/dependency-injection/dart/lib/app_component.dart

@@ -43,14 +43,12 @@ import 'providers_component.dart';
 )
 class AppComponent {
   final UserService _userService;
-  String title;
+  final String title;
 
   //#docregion ctor
-  AppComponent(Config config, this._userService) {
-    title = config.title;
-  }
-
+  AppComponent(Config config, this._userService) : title = config.title;
   // #enddocregion ctor
+
   bool get isAuthorized {
     return user.isAuthorized;
   }
@@ -64,6 +62,6 @@ class AppComponent {
   }
 
   String get userInfo => 'Current user, ${user.name}, is'
-        '${isAuthorized ? "" : " not"} authorized. ';
+      '${isAuthorized ? "" : " not"} authorized. ';
 }
 // #enddocregion

public/docs/_examples/dependency-injection/dart/lib/app_component_1.dart

@@ -14,7 +14,7 @@ import 'heroes/heroes_component_1.dart';
       <my-heroes></my-heroes>''',
     directives: const [CarComponent, HeroesComponent])
 class AppComponent {
-  var title = 'Dependency Injection';
+  final String title = 'Dependency Injection';
 }
 // #enddocregion
 

public/docs/_examples/dependency-injection/dart/lib/app_component_2.dart

@@ -25,11 +25,10 @@ import 'logger_service.dart';
       const Provider('app.config', useValue: CONFIG)
     ])
 class AppComponent {
-  String title;
+  final String title;
 
   // #docregion ctor
-  AppComponent(@Inject('app.config') Config config) {
-    title = config.title;
-  }
+  AppComponent(@Inject('app.config') Config config)
+      : title = config.title;
+  // #enddocregion
 }
-// #enddocregion

public/docs/_examples/dependency-injection/dart/lib/car/car_component.dart

@@ -23,6 +23,7 @@ class CarComponent {
   final Car car;
 
   CarComponent(this.car);
+
   Car factoryCar = (new CarFactory()).createCar();
   Car injectorCar = useInjector();
   carNoDi.Car noDiCar = new carNoDi.Car();

public/docs/_examples/dependency-injection/dart/lib/car/car_factory.dart

@@ -4,9 +4,8 @@ import 'car.dart';
 // BAD pattern!
 class CarFactory {
   Car createCar() {
-    var car = new Car(createEngine(), createTires());
-    car.description = 'Factory';
-    return car;
+    return new Car(createEngine(), createTires())
+      ..description = 'Factory';
   }
 
   Engine createEngine() => new Engine();