php - Using Exceptions to control application flow -

i writing web app in php , have decided use exceptions (duh!).

i not find answer whether putting try , catch blocks in functions considered bad code.

i using exceptions handle database errors (application errors handled via simple function adds them array , displayed user). try blocks placed on functions require database connection.

the code in question is:

public function db_conn_verify() {     if(!isset($this->_mysqli)){         throw new exception("network error: database connection not established.");     } else {         return null;     } } 

and example function using code:

public function get_users() {     try {         $this->db_conn_verify();          //rest of function code          return true;      } catch(exception $e) {         core::system_error('function get_users()', $e->getmessage());         return false;     } } 

also better extend exception class , use new exception class handle application errors?

thanks

i suggest use this:

public function get_users() {          try {             if( !isset($this->_mysqli) ) {                  throw new exception("network error: database connection not established.");             }              //rest of function code          } catch(exception $e) {             core::system_error('function get_users()', $e->getmessage());         } } 

i prefer use exends of exception, same. exdending exception can see php documentation example #5

edit: immediate use of try-catch on database connection error can try this:

try{     $mysqli = new mysqli("localhost", "user", "password", "database");     if ($mysqli->connect_errno) {         throw new exception("network error: database connection not established.");     } } catch(exception $e) {   core::system_error('function get_users()', $e->getmessage()); }