title: Shopping cart array session for empty value
body: <p>I'm currently doing e-commerce website for fyp, selling wide range of products, and have a slight confusion about shopping cart implementation. It supposed to add to session with optional size and color (for clothes etc). </p>
  
  <p>My idea:</p>
  
  <p><code>array('code'=&gt;array('color'='','size'=&gt;'','qty'=&gt;'')</code></p>
  
  <p>Color and size are empty if not available. Is this a good practice to do? Can you suggest more proper way to do this?</p>