https://wiki.php.net/rfc/argument_unpacking
n PHP 5.6 and later, argument lists may include the ... token to denote that the function
accepts a variable number of arguments. The arguments will be passed into the given variable as an array; for example:
Example #13 Using ... to access variable arguments
<?php
function sum(...$numbers) {
$acc = 0;
foreach ($numbers as $n) {
$acc += $n;
}
return $acc;
}
echo sum(1, 2, 3, 4);
?>