[samdalton]

It shouldn't be ok to write code that is known to throw an error, and handle it by suppressing that error. Silently failing code is just a bug waiting to happen.

It's also making the interpreter do unnecessary error handling work when a simple "if ($_GET['foobar'])" would suffice.

[philjackson]

It should be ok (the poor PHP implementation aside). Auto-vivification is something that's very useful in Perl and I miss it greatly in the languages I program in now. Being able to do this:

    $one->{ two }->{ three } = [ $four ]

Without having to check every link for definedness makes for cleaner code, IMO. Making it optional "suppressing that error" would be a good middle-ground.

Coffeescipt has the existential operator, not quite on a par with Perl's autovivification, which allows:

    zip = lottery.drawWinner?().address?.zipcode

[samdalton]

The Coffeescript ? operator is certainly quite handy. I suppose it's explicit nature is what helps, as information on the error you're trying to mask is built into the syntax. With @ in PHP however, you simply don't know what it's trying to stop, and what undesirable affects it may cause, which I think is the main objection to it.