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

On 17/02/06, Jochem Maas <jochem@iamjochem.com> 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); > [...] > OUTPUTS (on php5.0.4): > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > bool(true) > bool(true) > bool(true) > bool(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?) The rules are simple enough, and listed in the documentation here: http://www.php.net/manual/en/language.operators.comparison.php#AEN4390 But if you apply those comparison rules to your four expressions, you'd expect to see bool(true) bool(false) bool(true) bool(false) What you need to know to explain your results is that internally, PHP doesn't do a greater-than comparison, it converts them into less-than-or-equals by reversing the values. So your expressions become: $a < $b $b <= $a $b < $a $a <= $b Now if you apply the comparison rules to your arrays using those rewritten operations, you get true every time. Fun eh? -robin