On Sun, Aug 17, 2008 at 6:10 PM, Kristina Anderson <[EMAIL PROTECTED]> wrote: > Hi all. I have a question regarding the below syntax > > $result = isset($a['c']) ? $a['c'] : NULL; > > > This is testing two conditions, first if $a['c'] is set, and then, if $a > ['c'] is NULL...correct?
No. The x ? a : b construct is called the "ternary operator". The following example: $x ? $a : $b could be read "If $x is true, the expression evaluates to $a. Otherwise, the expression evaluates to $b.". It's basically a shorthand expression for if / else. Mike > What would $result be if $a['c'] is set but is not NULL? The same as > if $a['c'] was not set? or...? > > I've seen similar syntax before, in some code Tedd & I were working > with a couple of months back...and just want to make sure I fully > understand what is actually happening with it. > > Thanks. > > -- Kristina > >> On Sun, Aug 17, 2008 at 4:49 PM, Michael B Allen <[EMAIL PROTECTED]> > wrote: >> > Is it ok to access non-existent array elements? >> > >> > Will accessing an array element using a key that does not exist > always >> > return NULL? >> >> it depends on how you have warnings configured. you might be getting >> them in your log, for example... i believe the result of accessing a >> non-existent array element is undefined. >> >> if i were you, i'd prob'ly ask if it exists first: >> >> <?php >> >> $result = isset($a['c']) ? $a['c'] : NULL; >> >> /** OR **/ >> >> $result = array_key_exists('c', $a) ? $a['c'] : NULL; >> >> ?> >> >> see: >> >> http://us2.php.net/function.isset >> http://us2.php.net/function.array-key-exists >> >> >> justin >> -- >> http://justinhileman.com >> _______________________________________________ >> New York PHP Community Talk Mailing List >> http://lists.nyphp.org/mailman/listinfo/talk >> >> NYPHPCon 2006 Presentations Online >> http://www.nyphpcon.com >> >> Show Your Participation in New York PHP >> http://www.nyphp.org/show_participation.php >> >> > > > _______________________________________________ > New York PHP Community Talk Mailing List > http://lists.nyphp.org/mailman/listinfo/talk > > NYPHPCon 2006 Presentations Online > http://www.nyphpcon.com > > Show Your Participation in New York PHP > http://www.nyphp.org/show_participation.php > -- Michael B Allen PHP Active Directory SPNEGO SSO http://www.ioplex.com/ _______________________________________________ New York PHP Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk NYPHPCon 2006 Presentations Online http://www.nyphpcon.com Show Your Participation in New York PHP http://www.nyphp.org/show_participation.php