title: PHP array assigned with and
body: <p>Just learning php and looking into someone else's code. I'm not sure what is happening in this function with the word 'and' on the left side of the = operator. It seems like it is a 'silent' if is being used eg.
   if $arry =true and $array2 = true then $array2 += 'somthing';</p>
  
  <p>I cant seem to find any reference to this anywhere online.</p>
  
  <pre><code>  function get_list_filter($filter = array()) {
       global $current_user;
      $sql = array();
      $filter["clientID"]         and $sql[] = sprintf("(WD_domain.clientID = %d)",$filter["clientID"]);
      $filter["showDomainName"]   and $sql[] = sprintf("(WD_domain.domain LIKE '%%%s%%')",$filter["showDomainName"]);
      $filter["showManaged"]      and $sql[] = sprintf("(WD_domain.managed = %d)",$filter["showManaged"]);
      return $sql;
    }
  </code></pre>