Re: Re: isset($a->b) even if $a->b = null

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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
> >
> > --
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> >
> >
>
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