PHP/Statement/Exception

Catching Exceptions in PHP 5

   <source lang="html4strict">

<?php

       class MyException extends Exception {
       }
       class AnotherException extends Exception {
       }
       class ThrowExample {
               public function makeMyException() {
                       throw new MyException();
               }
               public function makeAnotherException() {
                       throw new AnotherException();
               }
               public function makeError() {
                       throw new Exception();
               }
       }
       $inst = new ThrowExample();
       try {
               $inst->makeMyException();
       } catch(MyException $e) {
               echo "Caught "MyException"\n";
       }
       try {
               $inst->makeAnotherException();
       } catch(MyException $e) {
               echo "Caught "MyException"\n";
       } catch(AnotherException $e) {
               echo "Caught "AnotherException"\n";
       }
       try {
               $inst->makeError();
       } catch(MyException $e) {
               echo "Caught "MyException"\n";
       } catch(AnotherException $e) {
               echo "Caught "AnotherException"\n";
       }

?>

 </source>
   
  

extends Exception to create your own exception

   <source lang="html4strict">

<?php class MyException extends Exception {

   function __construct($language,$errorcode) { 
       $this->language = $language;
       $this->errorcode = $errorcode;
   } 
   function getMessageMap() {
       $errors = file("errors/".$this->language.".txt");
       foreach($errors as $error) {
            list($key,$value) = explode(",",$error,2);
            $errorArray[$key] = $value;
       }
       return $errorArray[$this->errorcode];
   }  

} try {

   throw new MyException("english",4);

} catch (MyException $e) {

   echo $e->getMessageMap();

} ?>

 </source>
   
  

Using Custom Exceptions to Handle Different Circumstances

   <source lang="html4strict">

<?php class MyException extends Exception {

 public function summarize() {

$ret = "

\n";
    $ret .=  "msg: ".$this->getMessage()."\n"
         ."code: ".$this->getCode()."\n"
         ."line: ".$this->getLine()."\n"
         ."file: ".$this->getFile()."\n";
    $ret .= "

\n";

   return $ret;
 }

} class FileNotFoundException extends MyException { } class FileOpenException extends MyException { } class Reader {

 function getContents( $file ) {
     throw new FileNotFoundException( "could not find "$file"" );
     throw new FileOpenException( "unable to open "$file"" );
 }

} $reader = new Reader(); try {

 print $reader->getContents( "blah.txt" );

} catch ( FileNotFoundException $e ) {

 print $e->summarize();

} catch ( FileOpenException $e ) {

 print $e->summarize();

} catch ( Exception $e ) {

 die("unknown error");

} ?>

 </source>
   
  

Using PHP 5 exception handling

   <source lang="html4strict">

<?php function errors_to_exceptions($code, $message) {

  throw new Exception($code, $message); 

} set_error_handler("errors_to_exceptions"); try {

 $connection = mysql_connect($host, $user, $password); 
 mysql_select_db($database, $connection); 
 $query = "SELECT page_id,link_text,parent_id FROM menus WHERE page_id="$pid""; 
 $result = mysql_query($query); 
 if(mysql_num_rows($result) == 0) 
    echo "Invalid page request -- click <a href=\"" . $_SERVER["PHP_SELF"] . "?pid=1\">here</a> to continue.</h2>\n"; 
 else { 
    $value = mysql_fetch_object($result); 
 } 

}catch (Exception $e) {

printf("

Caught exception: %s.

\n", $e->getMessage());

} ?>

 </source>