strlen of a non existing variable in PHP

Question

I have a code in PHP something like this

 if (strlen($profile['current-employer']) == 0)
     break;
 else
     return a;

Now in some cases $profile['current-employer'] can be non-existent, now here my question is in the case of non-existent variable what strlen will result... (This is related with QueryHome code)

Answer 1

strlen of a non-existing variable is zero :)