title: check if storage is empty with ionic2
body: <p>Ionic2 does save data into my websql or indexdb. i'm trying to write an argumentative statement to check if the storage is empty it should do something else or the other way round. but i'm finding it hard to check if the storage value is empty</p>
  
  <pre><code> usercomment($event, item){
     if(this.storage.get('fullname')==null){
      this.navCtrl.push(signupPage,item)
     }else{
       this.navCtrl.push(commentPage,item)
     }
    }
  </code></pre>