title: check if data passed from laravel to vue exists
body: <p>Sometimes I need to pass data from my controller to the view and sometimes I dont!
  But when theres no data passed I get this error:</p>
  
  <blockquote>
    <p>Undefined variable: tutorial (View:
    /var/www/html/resources/views/home.blade.php)</p>
  </blockquote>
  
  <p><strong>No data example:</strong></p>
  
  <pre><code>public function index()
  {
      return view('home');
  } 
  </code></pre>
  
  <p><strong>Containg data example</strong></p>
  
  <pre><code>public function tutorial()
  {
      return view('home', ['tutorial' =&gt; 'Welcome to myproject, lets get started!!!']);
  }
  </code></pre>
  
  <p>Blade:</p>
  
  <pre><code>beforeMount()
  {
      let tutorial = {{ var_export($tutorial) }} // ERROR!!
      if (tutorial) {
          return
      }
      this.reloadData()
  }
  </code></pre>
  
  <p>I think I can do this way in my index function:</p>
  
  <pre><code>public function index()
  {
      return view('home', ['tutorial' =&gt; []);
  }
  </code></pre>
  
  <p>But its just gross!! Theres anyway to check if data passed from laravel exists in my vue??</p>