yes, but that assumes you have a defined class. if $a comes from mysql_fetch_object() for instance you have just a stdobject, and this method will produce an error. On 17/08/07, Michael Preslar <mpreslar@xxxxxxxxx> wrote: > Found something. > > For class variables.. > > http://us.php.net/manual/en/function.property-exists.php > > class a { > var $b; > } > > if (property_exists('a','b')) { > print "yes\n"; > } > > > On 8/17/07, Olav Mørkrid <olav.morkrid@xxxxxxxxx> wrote: > > the test i need should give the following results: > > > > - FALSE when $a->b does not exist at all > > - TRUE when $a->b = null > > - TRUE when $a->b = <any value> > > > > empty() gives true for both $a->b = null and not setting any value, so > > that's no good. > > > > borokovs suggestion seems to miss the purpose. > > > > anyone else? > > > > On 17/08/07, Colin Guthrie <gmane@xxxxxxxxxxxxxx> wrote: > > > Olav Mørkrid wrote: > > > > how do i test if a property of a stdclass object is set, even if its > > > > value is null, similar to how array_key_exists() works for arrays. > > > > > > > > the following method fails: > > > > > > > > $a->b = null; > > > > if(isset($a->b)) > > > > echo "yes"; > > > > > > > > and property_exists() seems only to work for defined objects. > > > > > > > > hope someone can help. thanks! > > > > > > You can try: > > > unset($a-b) > > > > > > Or change isset() to empty(). > > > > > > empty() catches more than isset() e.g. '' (empty string), false, 0 etc. > > > are considered "empty". Depending on your logic it can still be very > > > useful. It is a language construct rather than a function so it's also > > > efficient. > > > > > > Col > > > > > > -- > > > PHP General Mailing List (http://www.php.net/) > > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
