Re: '1.8' == 1.8 can return false

I'd take that as proof of a design flaw in having php doing string to float comparison by casting the string to float instead of the float to a string, but you've got me - the documentation does say the string will be converted to a float and not vice-versa. If it wouldn't be a bad BC break, I think there'd be a lower WTF by doing the cast the other way. "==" means are they the same and "===" means are they the SAME. With "==", '1.8' should match any float that would be displayed as 1.8. (Of course, with "===" they aren't even the same type, so you're false from the start.) I say "should" from an anti-WTF perspective. Again, I must bow to the spec and you have me there. Thanks for saving me the hours of discovering all this via debugging. Please consider the switching of casts for string==float for the suggestion box. - Todd On Fri, 2008-04-11 at 20:29 -0700, Rasmus Lerdorf wrote: > There is no bug here. Please read: > > http://docs.sun.com/source/806-3568/ncg_goldberg.html > > -Rasmus > > Todd Ruth wrote: > > I'm thinking there must be a bug in the heart of php > > causing this. I'll debug it, but I haven't looked at > > php source code in a few years and would like a tip as > > to which files are involved in evaluating "==". Here > > is a fragment from my code and the output: > > > > ... > > print "<pre>\n"; > > var_dump($max); > > var_dump($nms); > > var_dump($nms == $max); > > $max = (float)$max; > > $nms = (string)$nms; > > var_dump($max); > > var_dump($nms); > > var_dump($nms == $max); > > $max = (string)$max; > > $nms = (float)$nms; > > var_dump($max); > > var_dump($nms); > > var_dump($nms == $max); > > print "</pre>\n"; > > ... > > > > string(3) "1.8" > > float(1.8) > > bool(false) > > float(1.8) > > string(3) "1.8" > > bool(true) > > string(3) "1.8" > > float(1.8) > > bool(true) > > > > I found this using php 5.2.3. I just upgraded to php 5.2.5 > > and am receiving the exact same result. Obviously, I can't > > reproduce it with a simple var_dump("1.8"==1.8). :( > > I guess something is getting corrupted, and I will add debug > > output until I find out what (or Murphy removes the problem > > by adding debug output; then I'm not sure what I'll do). > > > > Thanks for any tips on which files I should look at it. >