array_merge() and array_merge_recursive()

array_merge() and array_merge_recursive() can now also be called without an argument:

var_dump(array_merge());
var_dump(array_merge_recursive());

Executing the code shown above will print the output shown below:

array(0) {
}
array(0) {
}

When array_merge() and array_merge_recursive() are called without an argument they return an empty array. This is useful when the spread operator ... is used as ...$arrays may be unpacked to an empty list in which case array_merge(...$arrays), for instance, leads to array_merge() being called without an argument.