anchor.diff:    We can chain expressions through multiple pipes:
   +makeExample('template-syntax/ts/app/app.component.html', 'pipes-2')(format=".")
   :marked
  -  We can also [apply parameters](./pipes.html#parameterizing-a-pipe) to a pipe:
  +  And we can also [apply parameters](./pipes.html#parameterizing-a-pipe) to a pipe:
   +makeExample('template-syntax/ts/app/app.component.html', 'pipes-3')(format=".")
   
   block json-pipe
  
positive.code:   ### The safe navigation operator ( ?. ) and null property paths
  
    The Angular **safe navigation operator (`?.`)** is a fluent and convenient way to guard against null and undefined values in property paths.
    Here it is used to protect against against a view render failure if the `currentHero` is null:
  +makeExample('template-syntax/ts/app/app.component.html', 'safe-2')(format=".")
  
  block dart-safe-nav-op
  
negative.code: +makeExample('template-syntax/ts/app/app.component.html', 'safe-1')(format=".")
  :marked
    The view still renders but the displayed value is blank; we see only "The title is" with nothing after it.
    That is reasonable behavior. At least the app doesn't crash.
  
    Suppose the template expression involves a property path, as in this next example
    where we’re displaying the `firstName` of a null hero.
  
  code-example(language="html").
    The null hero's name is {{nullHero.firstName}}
  