具体来说,“@有它的用途”：
Now one really should use the
@operator very sparingly,handling
errors instead of suppressing them. But there are a small number of
situations I can think of where one might need to suppress some PHP
errors. Let me offer two examples :
You Could be using some large external library which has made use of the
@,and so need to be able to ignore those errors as the author
of the library intended,otherwise your program is going to trip up
where it doesn’t need to. You Could edit the library,but it might
take a lot of time,and your changes would again have to be applied
each time the author releases an update to the library.Another example might be when the
fopenfunction is used to open an external URL,and the URL cannot be opened for one of many possible
reasons. The function returnsfalseto indicate a fail,which is
great,but to quote the PHP manual,“an error of levelE_WARNINGis
generated” too,not so great — it should really result in an exception
being thrown instead,as this is an irregular situation,but one which
should be expected.
In this case one would like to be able to ignore
the error,and continue with the program execution,explicitly
responding in an appropriate way – exactly what exceptions are for!
There is,however,a way to convert the error to an exception and so
avoid using the@in this situation. In your custom error handler
(which is where we find ourselves in this post),throw an
ErrorException – this then requires you to explicitly catch and handle
it in the code that was using the@before,which is a better way of handling errors.