Re: anyone care to explain the logic behind this output ....

(Don't you hate it when people forget to post back to the list...) The secret is actually hidden in the docs, http://php.net/manual/en/language.operators.comparison.php When comparing $a < $b, you compare the first value of $a (0) to the value with the same key in $b (1). 0 < 1 --> true When you compare $b < $a, the first value of $b is 0, with a key of 1. The value in $a is 1, 0 < 1 --> true The discussion on php-dev, where you found this example, reveals that PHP makes the assumption that $a > $b == $b < $a. This means that they can reuse the less than function for greater than calls. In this case the assumption isn't actually valid. $a > $b should be 0 > 1 --> false. David Jochem Maas wrote: > THIS CODE > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > php -r ' > $a = array(0, 1); > $b = array(1 => 0, 0 => 1); > var_dump($a < $b); // true > var_dump($a > $b); // true > var_dump($b < $a); > var_dump($b > $a); > > echo "\n\$a:\n"; var_dump((bool)$a, (int)$a, (string)$a, intval($a), > strval($a)); > echo "\n\$b:\n"; var_dump((bool)$b, (int)$b, (string)$b, intval($b), > strval($b)); > ' > > OUTPUTS (on php5.0.4): > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > bool(true) > bool(true) > bool(true) > bool(true) > > $a: > bool(true) > int(1) > string(5) "Array" > > $b: > bool(true) > int(1) > string(5) "Array" > > WHICH MEANS THAT: > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > one the one hand $a is greater than AND less than $b > but on the other hand casting $a OR $b to either a boolean, > integer or string results in the exact same value. ie: > > php -r ' > $a = array(0, 1); $b = array(1 => 0, 0 => 1); > var_dump( ((($a > $b) === ($b > $a)) === ((int)$a === (int)$b)) ); // > WTF IT'S TRUE > ' > > weird? I think so - but then again I'd never test that array $a is > greater than array $b because this is meaningless to me (in what way is $a > greater - how is this quantified, what 'rules' determine 'greatness' in > this context?) > > PS - changing the $b array to something else (anything else as far as i > can tell) > causes the weirdness to not occur - which gives me the impression this > could be a bug, > anyone else get this impression? for instance try changing the second > line of > the code above to (merely switching the order or the defined array > elements): > > $b = array(0 => 1, 1 => 0); >