anchor.diff:    ## The Lifecycle Hooks
     Directive and component instances have a lifecycle
     as Angular creates, updates, and destroys them.
  -  
  +
     Developers can tap into key moments in that lifecycle by implementing
     one or more of the "Lifecycle Hook" interfaces, all of them available
  -  in the `angular2/core` library. 
  -  
  +  in the `angular2/core` library.
  +
     Here is the complete lifecycle hook interface inventory:
   
      * `OnInit`
  
positive.code:   * `ngAfterViewInit` - after component's view(s) are initialized
    * `ngAfterViewChecked` - after every check of a component's view(s)
    * `ngOnDestroy` - just before the directive is destroyed.
   
    The [live example](/resources/live-examples/lifecycle-hooks/ts/plnkr.html) demonstrates
    these hooks.
  
  
negative.code:   # Component Lifecycle
    A Component has a lifecycle managed by Angular itself. Angular creates it, renders it, creates and renders its children,
    checks it when its data-bound properties change, and destroys it before removing it from the DOM.
  
    Angular offers **Lifecycle hooks**
    that give us visibility into these key moments and the ability to act when they occur.
  
    We cover these hooks in this chapter and demonstrate how they work in code.
  
    [Live Example](/resources/live-examples/lifecycle-hooks/ts/plnkr.html)
  
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