Uknown ?? in symfony's public/index.php?

Question

While I was looking over symfony's public/index.php I came across the following snippet of code:

$env = $_SERVER['APP_ENV'] ?? 'dev';
$debug = (bool) ($_SERVER['APP_DEBUG'] ?? ('prod' !== $env));

Therefore I performed the following searches:

But still I cannot figure out what the operator ?? actually means. Can you provide me info regarding this operator/syntax ?

it's a PHP 7+ exclusive ternary operator (aka: Null Coalescing Operator) http://php.net/manual/en/language.operators.comparison.php — Funk Forty Niner, Jul 15 '18 at 13:09

score 5 · Accepted Answer · answered Jul 15 '18 at 13:10

5

it's shortest version of

$env = isset($_SERVER['APP_ENV']) ? $_SERVER['APP_ENV'] : 'dev';

was added in PHP 7

answered Jul 15 '18 at 13:10

MrSmile

1 Answers1