Re: Implicit isset/isempty check on short-ternary operator

On 8/04/11 4:41 AM, Rasmus Lerdorf wrote:

On 4/7/11 2:30 PM, Rafael Dohms wrote:

On Thu, Mar 31, 2011 at 7:46 PM, Ben Schmidt <mail_ben_schmidt@yahoo.com.au> wrote:

On 1/04/11 3:29 AM, David Coallier wrote:

Hey there, I've been working on a little patch that will allow variables ($1) in a short-ternary operation to go through an implicit isset (zend_do_isset_or_isempty) check so that the average use-case for the short-ternary operator doesn't yield in a notice whenever the first variable of the expression isn't set. So the use-case I'm considering is the following: <?php $list = array('name' => 'list'); echo $list['name'] ?: 'List not set.' . PHP_EOL; echo $list['name-notset'] ?: 'List not set.' . PHP_EOL; ?> This example, which we all know, will result in a notice for the second echo statement because the requested array-key doesn't actually exist in the array.

I'm not familiar with the construct, but to be honest, I fail to see how it is useful without the suppression of the notice. I mean, it's a shorthand for isset($var)?$var:$something_else isn't it? That presupposes that $var may not be set, but that you've accounted for that fact, so don't want a notice about it. Obviously the isset() can only be applied if the 'left hand side' is an lval, but I think it makes sense to apply it whenever it is an lval. So a big +1 from me. Ben.

Its also a +1 for me, it would make the ternary operator much more useful to me e remove lots of verbose code for handling arrays.

Well, it would change the semantics. And Ben, no, it isn't shorthand for an isset() it is like writing (boolean)$var?$var:$something

Thanks for the clarification, Rasmus. That makes sense. I still think the patch would be very useful, though I can also see how an argument could be made for keeping the warning. In my opinion, the case for removing the warning is stronger than for keeping it. Ben.