Catching multiple exception types in one catch block

Question

I d like a cleaner way to obtain the following functionality  to catch AError and BError in one block   try          something      catch  AError  BError  e         handler1   e     catch  Exception  e         handler2   e       Is there any way to do this  Or do I have to catch them separately   AError and Berror have a shared base class  but they also share it with other types that I d like to fall through to handler2  so I can t just catch the base class

User · Answer

This article covers the question electrictoolbox.com/php-catch-multiple-exception-types. Content of the post copied directly from the article:

Example exceptions

Here's some example exceptions that have been defined for the purposes of this example:

class FooException extends Exception 
{
  public function __construct($message = null, $code = 0) 
  {
    // do something
  }
}

class BarException extends Exception 
{
  public function __construct($message = null, $code = 0) 
  {
    // do something
  }
}

class BazException extends Exception 
{
  public function __construct($message = null, $code = 0) 
  {
    // do something
  }
}

Handling multiple exceptions

It's very simple - there can be a catch block for each exception type that can be thrown:

try 
{
  // some code that might trigger a Foo/Bar/Baz/Exception
}

catch(FooException $e) 
{
  // we caught a foo exception
}

catch(BarException $e) 
{
  // we caught a bar exception
}

catch(BazException $e) 
{
  // we caught a baz exception
}

catch(Exception $e) 
{
  // we caught a normal exception
  // or an exception that wasn't handled by any of the above
}

If an exception is thrown that is not handled by any of the other catch statements it will be handled by the catch(Exception $e) block. It does not necessarily have to be the last one.

User · Answer

Hmm  there are many solution written for php version lower than 7 1    Here is an other simple one for those who doesn t want catch all exception and can t make common interfaces    lt  php  ex   NULL try                   catch  FirstException  ex           just do nothing here   catch  SecondException  ex           just do nothing here   if   ex     NULL           handle those exceptions here      gt

User · Answer

Coming in PHP 7 1 is the ability to catch multiple types   So that this    lt  php try                   catch  FirstException  ex         this- gt manageException  ex     catch  SecondException  ex         this- gt manageException  ex       gt    and   lt  php try      catch  FirstException   SecondException  ex         this- gt manageException  ex       gt    are functionally equivalent

User · Answer

As an extension to the accepted answer  you could switch the type of Exception resulting in a pattern that is somewhat like the original example   try           Try something    catch  Exception  e         switch  get class  e              case  AError           case  BError                  Handle A or B             break           case  CError                  Handle C             break           case default                 Rethrow the Exception             throw  e

User · Answer

Besides fall-through  it s also possible to step over by using goto  It s very useful if you want to see the world burn    lt  php  class A Error extends Exception    class B Error extends Exception    class C Error extends Exception     try       throw new A Error       catch  A Error  e    goto abc    catch  B Error  e    goto abc    catch  C Error  e    abc      var dump get class  e        echo  Gotta Catch  Em All n       3v4l org

User · Answer

As of PHP 7 1     catch  AError   BError  e         handler1   e       interestingly  you can also   catch  AError   BError  e         handler1   e     catch  CError  e       handler2  e     catch Exception  e       handler3  e       and in earlier versions of PHP   catch Exception  ex       if  ex instanceof AError             handle a AError       elseif  ex instanceof BError             handle a BError       else          throw  ex   an unknown exception occured  throw it further

User · Answer

A great way is to use set exception handler   Warning    with PHP 7  you might get a white screen of death for fatal errors   For example  if you call a method on a non-object you would normally get Fatal error  Call to a member function your method   on null and you would expect to see this if error reporting is on   The above error will NOT be caught with  catch Exception  e   The above error will NOT trigger any custom error handler set by set error handler    You must use catch Error  e     to catch errors in PHP7    This could help   class ErrorHandler      public static function excep handler  e                print r  e           set exception handler array  ErrorHandler   excep handler

User · Answer

As of PHP 8 0 you can use even cleaner way to catch your exceptions when you don t need to output the content of the error  from variable  e   However you must replace default Exception with Throwable  try          something      catch  AError   BError        handler1     catch  Throwable        handler2

User · Answer

Update  As of PHP 7 1  this is available  The syntax is  try          Some code      catch AError   BError  e           Handle exceptions   catch Exception  e           Handle the general case    Docs  https   www php net manual en language exceptions php example-294 RFC  https   wiki php net rfc multiple-catch Commit  https   github com php php-src commit 0aed2cc2a440e7be17552cc669d71fdd24d1204a  For PHP before 7 1  Despite what these other answers say  you can catch AError and BError in the same block  it is somewhat easier if you are the one defining the exceptions   Even given that there are exceptions you want to  quot fall through quot   you should still be able to define a hierarchy to match your needs  abstract class MyExceptions extends Exception     abstract class LetterError extends MyExceptions     class AError extends LetterError     class BError extends LetterError     Then  catch LetterError  e         voodoo    As you can see here and here  even the SPL default exceptions have a hierarchy you can leverage  Additionally  as stated in the PHP Manual   When an exception is thrown  code following the statement will not be executed  and PHP will attempt to find the first matching catch block   This means you could also have class CError extends LetterError     which you need to handle differently than AError or BError  so your catch statement would look like this  catch CError  e         voodoo   catch LetterError  e         voodoo    If you had the case where there were twenty or more exceptions that legitimately belonged under the same superclass  and you needed to handle five  or whatever large-ish group  of them one way and the rest the other  you can STILL do this  interface Group1     class AError extends LetterError implements Group1     class BError extends LetterError implements Group1     And then  catch  Group1  e      Using OOP when it comes to exceptions is very powerful  Using things like get class or instanceof are hacks  and should be avoided if possible  Another solution I would like to add is putting the exception handling functionality in its own method  You could have function handleExceptionMethod1 Exception  e          voodoo    function handleExceptionMethod2 Exception  e          voodoo    Assuming there is absolutely no way you can control exception class hierarchies or interfaces  and there almost always will be a way   you can do the following  try       stuff     catch ExceptionA  e         this- gt handleExceptionMethod1  e     catch ExceptionB  e         this- gt handleExceptionMethod1  e     catch ExceptionC  e         this- gt handleExceptionMethod1  e     catch Exception  e         this- gt handleExceptionMethod2  e      In this way  you are still have a only single code location you have to modify if your exception handling mechanism needs to change  and you are working within the general constructs of OOP

User · Answer

Another option not listed here is to use the code attribute of an exception  so you can do something like this   try        if  1      foo              throw new Exception sprintf  Invalid foo   s   serialize  foo    1              if  2      bar            throw new Exception sprintf  Invalid bar   s   serialize  foo    2           catch  Exception  e         switch   e- gt getCode               case 1                 Special handling for case 1             break           case 2                 Special handling for case 2             break           default                  Special handling for all other cases

User · Answer

Here s a reasonable alternative if you don t have control over defining the exceptions  Use the name of the exception variable to categorize the exceptions when they are caught  Then check for the exception variable after the try catch block    ABError   null  try          something   catch  AError  ABError        let the exception fall through   catch  BError  ABError        let the exception fall through   catch  Exception  e        handler2  e     if   ABError        handler1  ABError       This somewhat odd looking approach is probably only worth it if there is a lot of duplication between catch block implementations

User · Answer

In PHP  gt   7 1 this is possible  See this answer   If you can modify the exceptions  use this answer  If you can t  you could try catching all with Exception and then check which exception was thrown with instanceof  try          something      catch  Exception  e         if   e instanceof AError OR  e instanceof BError              It s either an A or B exception        else              Keep throwing it          throw  e           But it would probably be better to use multiple catch blocks as described in aforementioned answer  try          something      catch  AError  e        handler1   e      catch   BError  b        handler2   e

[php] Catching multiple exception types in one catch block

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