Below is a function which we can find in core Magento 2 code.
protected function createObject($type, $args)
{
return new $type(...array_values($args));
}
This function is instantiating $type (which is a string parameter) with the arguments $args (which is an array parameter).
What I am not getting is those 3 dots (...). Is this a valid syntax at all ? I never found such an object instantiation before !!
I tried to remove those dots and try to load a page. It gives fatal errors. So it seems that, those three dots are not accidentally come over there.
It seems like that code won't work for php-5.3 or lower versions. So it is something new which I couldn't find anywhere.
It is a variable-length argument lists. They are new to PHP 5.6.x. This example is from the PHP manual:
<?php
function sum(...$numbers) {
$acc = 0;
foreach ($numbers as $n) {
$acc += $n;
}
return $acc;
}
echo sum(1, 2, 3, 4);
?>