Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:101609
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain eordes.com from 209.85.128.177 cause and error)
To: Marco Pivetta <ocramius@gmail.com>
Cc: PHP Internals List <internals@lists.php.net>
References: <6fac0482-93fe-b15f-632c-1058232abcf0@eordes.com>
 <CADyq6sK9ji0Qj1vxCuEDscjRRLQCrSpLY+1kndR=8CoCpN1dEg@mail.gmail.com>
Message-ID: <bb9e2156-8835-f0ed-6089-c0d7d759152a@eordes.com>
Date: Wed, 17 Jan 2018 19:28:14 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.5.0
MIME-Version: 1.0
In-Reply-To: <CADyq6sK9ji0Qj1vxCuEDscjRRLQCrSpLY+1kndR=8CoCpN1dEg@mail.gmail.com>
Content-Type: multipart/alternative;
 boundary="------------B6B0C5A0F4AE95EDF00349F9"
Content-Language: es-CO
Subject: Re: [PHP-DEV] [RFC] [DISCUSSION] Improve null-coalescing operator
 (??) adding empty check (??:)
From: info@eordes.com (Lito)

--------------B6B0C5A0F4AE95EDF00349F9
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit

No $foo ?: 'default' , it's only equivalent to (isset($foo) && $foo) ? 
$foo : 'default' if $foo exists.

Also PHP has added ?? as null-coalescing operator that works with 
undefined variables/attributes/keys, my proposal is an improvement over 
this one.

I don't want to endorse usage of undefined variables, can be used in a 
large set of situations, like object attributes, array keys, etc...

Anyway thanks for your feedback.
Lito.

On 17/01/18 19:17, Marco Pivetta wrote:
> This:
>
> echo (isset($foo) && $foo) ? $foo : 'default';
>
> Is equivalent to:
>
> echo $foo ?: 'default';
>
> Please don't endorse usage of undefined variables.
>
> On 17 Jan 2018 19:00, "Lito" <info@eordes.com 
> <mailto:info@eordes.com>> wrote:
>
>     Related with Request #75833 https://bugs.php.net/bug.php?id=75833
>     <https://bugs.php.net/bug.php?id=75833>
>
>     >From PHP 7 null-coalescing operator is a great option to avoid a
>     previous exists check with isset.
>
>     But I think that this comaparison can be improved adding a ternary
>     operator like ??: and check also empty values.
>
>     Example:
>
>     --------------------------------------
>
>     <?php
>
>     $foo = '';
>
>     // Current response with ternary operator
>
>     echo $foo ?: 'default'; // 'defaut'
>
>     // Current response with null-coalescing operator
>
>     echo $foo ?? 'default'; // ''
>
>     // Possible response with ternary null-coalescing operator
>
>     echo $foo ??: 'default'; // 'defaut'
>
>     // Same response with current PHP available code
>
>     echo (isset($foo) && $foo) ? $foo : 'default'; // 'default'
>
>     /** ------------------------------- **/
>
>     $foo = false;
>
>     // Current response with ternary operator
>
>     echo $foo ?: 'default'; // 'defaut'
>
>     // Current response with null-coalescing operator
>
>     echo $foo ?? 'default'; // false
>
>     // Possible response with ternary null-coalescing operator
>
>     echo $foo ??: 'default'; // 'defaut'
>
>     // Same response with current PHP available code
>
>     echo (isset($foo) && $foo) ? $foo : 'default'; // 'default'
>
>     /** ------------------------------- **/
>
>     $foo = null;
>
>     // Current response with ternary operator
>
>     echo $foo ?: 'default'; // 'defaut'
>
>     // Current response with null-coalescing operator
>
>     echo $foo ?? 'default'; // 'defaut'
>
>     // Possible response with ternary null-coalescing operator
>
>     echo $foo ??: 'default'; // 'defaut'
>
>     // Same response with current PHP available code
>
>     echo (isset($foo) && $foo) ? $foo : 'default'; // 'default'
>
>     /** ------------------------------- **/
>
>     unset($foo);
>
>     // Current response with ternary operator
>
>     echo $foo ?: 'default'; // PHP Notice:  Undefined variable: foo
>
>     // Current response with null-coalescing operator
>
>     echo $foo ?? 'default'; // 'defaut'
>
>     // Possible response with ternary null-coalescing operator
>
>     echo $foo ??: 'default'; // 'defaut'
>
>     // Same response with current PHP available code
>
>     echo (isset($foo) && $foo) ? $foo : 'default'; // 'default'
>
>     --------------------------------------
>
>     What about?
>
>     Thanks!
>     Lito.
>
>     -- 
>     PHP Internals - PHP Runtime Development Mailing List
>     To unsubscribe, visit: http://www.php.net/unsub.php
>


--------------B6B0C5A0F4AE95EDF00349F9--