title: json_decode to array or to object
body: <p>Latly I came upon a question where someone asked me, why I turn the output of <code>json_decode</code> into an assoc array.</p>
  
  <p>For me it's easier to use assoc arrays than stdClasses and there are already many array_* functions which support data handling after I decode the json string.</p>
  
  <p>After a short performance test it turns out, that the conversion to an assoc array is about 20% faster than the conversion to stdClass.</p>
  
  <p>Nevertheless, the default behavior is <code>$assoc = false</code>. So I wonder, were are the benefits of using stdClasses when dealing with json data.
  Are there any json types which can't be represented in assoc arrays, but in stdClasses?</p>