anchor.diff:  
     :marked
       The template still refers to the old `hero` property.
  -    Bind to the new selectedHero property instead as follows:
  +    Bind to the new `selectedHero` property instead as follows:
   
   
     +makeExample('toh-2/ts/src/app/app.component.1.html', 'selectedHero-details', 'app.component.ts (template excerpt)')(format='.')
  
positive.code:   :marked
      ### Hide the empty detail with ngIf
  
      When the app loads, the `selectedHero` is undefined and won't be defined until you click a hero's name.
      Angular can't display properties of the undefined `selectedHero` and throws the following error,
      visible in the browser's console:
  
  
negative.code: 
    ## The road ahead
    You've expanded the Tour of Heroes app, but it's far from complete.
    An app shouldn't be one monolithic component.
    In the [next page](toh-pt3.html), you'll split the app into subcomponents and make them work together.
  