Re: Ranges for case statement and a WTF moment.

On 5 April 2011 16:28, Richard Quadling <rquadling@gmail.com> wrote: > Hi. > > I just wanted to quickly see if PHP supported ranges in its > switch/case statement (http://en.wikipedia.org/wiki/Ellipsis) > > <?php > $s = intval(date('s')); > switch($s) >        { >        case 0...9   : echo 'Between 0 and 9'; break; >        case 10...19 : echo 'Between 10 and 19'; break; >        case 20...29 : echo 'Between 20 and 29'; break; >        case 30...39 : echo 'Between 30 and 39'; break; >        case 40...49 : echo 'Between 40 and 49'; break; >        case 50...59 : echo 'Between 50 and 59'; break; >        default      : echo 'Unknown : ', $s; >        } > ?> > > Completely unexpectedly, the above code runs but produces the wrong output. > > Interestingly, altering the number of dots and adding spaces all > result in parse errors ... > > case 0..9 : // 2 dots, no spaces > case 0 .. 9 : // 2 dots, with spaces > case 0 ... 9 : // 3 dots, with spaces > > It was confusing that the initial code ran without a parse error, but > considering that it did, it would suggest that the case values are > actually meaningful in some way. > > php -r "var_dump(10...19);" > > Interesting output ... > > string(6) "100.19" > > And that took me a little while to work out. > > It's all to do with PHP's type juggling. > > 10...19 > > What I'm not sure is why the middle empty string is output as 0. > > "10" . . ".19" becomes "10" . "0" . ".19" > which becomes "100.19" > > Oddly, more . don't work. > > php -r "var_dump(10....19);" > > all result in parse errors. > > I don't know if this is a "bug" per se, but it is an oddity that I > though I'd share. > > And what is even more surprising is that the initial code works in the > PHP V4.0.0. So maybe an 11 years old bug. > > You really would have thought I'd have more to do with my time! > > Regards, > > Richard. Just tested PHP V3.0.11 and I get the same response. Seems that this is just the way it is. An oddity for since 1999-06-26 at least. Richard. -- Richard Quadling Twitter : EE : Zend @RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY