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Date: Sun, 27 Feb 2022 09:31:00 -0600
To: "php internals" <internals@lists.php.net>
Content-Type: text/plain
Subject: Re: [PHP-DEV] Re: Proposal for RFC to remove undefined arrayindexwarning when
 used ina ternary
From: larry@garfieldtech.com ("Larry Garfield")

On Sun, Feb 27, 2022, at 9:11 AM, Robert Landers wrote:
> On Sun, Feb 27, 2022 at 12:35 PM Mark Randall <marandall@php.net> wrote:
>
>> On 27/02/2022 09:12, Robert Landers wrote:
>> > I'd also venture that this warning has caused more harm than good, in
>> that
>> > writing "$var['something'] ?? null" is second nature when writing new
>> > code, even if there is practically no chance for a non-existent key.
>>
>>
>>
>> Using null coalesce should only be used when you know you have the
>> possibility of a missing key.
>>
>
> That can't always be known, or requires tracing the stack to see where
> it comes from and what modifies the array before it is passed to the
> function you are modifying, it is an array after all, not a formalized
> object with well-defined properties (which I'd prefer, but we can't always
> change what someone did 15 years ago just for the sake of changing it).

If you want to assign defaults to missing array keys, this is a generally good approach I've used with much success:

$arr = ['a' => 1, 'b' => 2];

$defaults = ['a' => 3, 'c' => 4];

$arr += $defaults;

If you're stuck with a pseudo-object hash like that, this is a clean way to guarantee you have values for each key.

That said, I'm also open to discussing null-safe array operators.  I can see lots of uses for that.

--Larry Garfield