Exception::__construct

(PHP 5, PHP 7, PHP 8)

Exception::__constructErstellt die Exception

Beschreibung

public Exception::__construct(string $message = "", int $code = 0, ?Throwable $previous = null)

Erstellt die Exception.

Parameter-Liste

message

Die auszugebende Beschreibung der Exception.

code

Die Fehlernummer der Exception.

previous

Die vorangegangene Exception, die für Exception-Verkettung verwendet werden soll.

Hinweis: Der Aufruf des Konstruktors der Klasse Exception aus einer Unterklasse ignoriert die Standardargumente, wenn die Eigenschaften $code und $message bereits gesetzt wurden.

Anmerkungen

Hinweis:

Die message is NICHT binary-safe.

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User Contributed Notes 3 notes

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45
talksonweb at gmail dot com
11 years ago
For those that haven't done exception chaining. Here's an example.

This allows you to add the previous exception to the next one and give yourself detailed information in the end as to what happened. This is useful in larger applications.

<?php
function theDatabaseObj(){
     if(
database_object ){
         return
database_object;
     }
     else{
         throw new
DatabaseException("Could not connect to the database");
     }
}

function
updateProfile( $userInfo ){
     try{
        
$db = theDatabaseObj();
        
$db->updateProfile();
     }
     catch(
DatabaseException $e ){
        
$message = "The user :" . $userInfo->username . " could not update his profile information";
        
/* notice the '$e'. I'm adding the previous exception  to this exception. I can later get a detailed view of
          where the problem began. Lastly, the number '12' is  an exception code. I can use this for categorizing my
         exceptions or don't use it at all. */
        
throw new MemberSettingsException($message,12,$e);
     }
}

try{
    
updateProfile( $userInfo );
}
catch(
MemberSettingsException $e ){
    
// this will give all information we have collected above.
    
echo $e->getTraceAsString();
}
?>
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3
mattsch at gmail dot com
11 years ago
Be aware that while $previous is quite useful in providing exception chaining and better traceability, none of the internal php exceptions (e.g. PDOException, ReflectionException, etc) are called internally within php with $previous in mind. 

So if your code throws an exception, recovers from it, then catches one of these internal php exceptions, recovers from it and throws another exception, you will not know the first exception that was thrown when calling getPrevious.

See: https://bugs.php.net/bug.php?id=63873
up
-6
ryan dot jentzsch at gmail dot com
7 years ago
Note that the code parameter is not the same as exit($code).
Also, the code argument in PHP 7 (possibly earlier versions) is cast to an int including negative values. The code below is completely valid:

<?php
try
{
    throw new \
Exception('Testing', -12.12);
}
catch (\
Exception $exception)
{
   
$code = $exception->getCode();
    if (
$code < 0)
    {
        exit(
abs($code));
    }
}
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