Now i found the problem that for new system to work, I have to upgrade to PHP 7
In PHP 7 we additionally get the ?? operator which rather than indicating extreme confusion which is how I would usually use two question marks together instead allows us to chain together a string of values. Reading from left to right, the first value which exists and is not null is the value that will be returned.
// $a is not set
$b = 16;
echo $a ?? 2; // outputs 2
echo $a ?? $b ?? 7; // outputs 16
This construct is useful for giving priority to one or more values coming perhaps from user input or existing configuration, and safely falling back on a given default if that configuration is missing. It's kind of a small feature but it's one that I know I'll be using as soon as my applications upgrade to PHP 7.
The administrator has disabled public write access.