Tech Vision school...Latest Tech News

3. Error Handling

The next feature we going to cover are the changes to Error Handling. Handling fatal errors in the past has been next to impossible in PHP. A fatal error would not invoke the error handler and would simply stop your script. On a production server, this usually means showing a blank white screen, which confuses the user and causes your credibility to drop. It can also cause issues with resources that were never closed properly and are still in use or even locked.

In PHP 7, an exception will be thrown when a fatal and recoverable error occurs, rather than just stopping the script. Fatal errors still exist for certain conditions, such as running out of memory, and still behave as before by immediately stopping the script. An uncaught exception will also continue to be a fatal error in PHP 7. This means if an exception thrown from an error that was fatal in PHP 5 goes uncaught, it will still be a fatal error in PHP 7.

I want to point out that other types of errors such as warnings and notices remain unchanged in PHP 7. Only fatal and recoverable errors throw exceptions.

In PHP 7, Error and Exception both implement the new Throwable class. What that means is that they basically work the same way. And also, you can now use Throwable in try/catch blocks to catch both Exception and Error objects. Remember that it is better practice to catch more specific exception classes and handle each accordingly. However, some situations warrant catching any exception (such as for logging or framework error handling). In PHP 7, these catch-all blocks should catch Throwable instead of Exception.