Re: [RFC] Saner string to number comparisons

Em ter, 26 de fev de 2019 às 09:28, Nikita Popov <nikita.ppv@gmail.com> escreveu: > Hi internals, > > I think it is well known that == in PHP is a pretty big footgun. It doesn't > have to be. I think that type juggling comparisons in a language like PHP > have some merit, it's just that the particular semantics of == in PHP make > it so dangerous. The biggest WTF factor is probably that 0 == "foobar" > returns true. > > I'd like to bring forward an RFC for PHP 8 to change the semantics of == > and other non-strict comparisons, when used between a number and a string: > > https://wiki.php.net/rfc/string_to_number_comparison > > The tl;dr is that if you compare a number and a numeric string, they'll be > compared as numbers. Otherwise, the number is converted into a string and > they'll be compared as strings. > > This is a very significant change -- not so much because the actual BC > breakage is expected to be particularly large, but because it is a silent > change in core language semantics, which makes it hard to determine whether > or not code is affected by the change. There are things we can do about > this, for example the RFC suggests that we might want to have a transition > mode where we perform the comparison using both the old and the new > semantics and warn if the result differs. > > I think we should give serious consideration to making such a change. I'd > be interested to hear whether other people think this is worthwhile, and > how we could go about doing it, while minimizing breakage. > > Regards, > Nikita > Hi Nikita, There's only one case that I'm not sure about > Comparison | Before | After > ------------------------------ > 0 == "" | true | false I know that a cast of am empty and non-empty string results into 0 ( https://3v4l.org/W0P3Z), but still, not sure about this one in specific. Best, -- Gabriel Caruso