So, to be honest, I'd never recommend writing a loop like this. It's a style favoured by a handful of old-school C programmers, and it is hard to read and maintain even for experienced devs.
Prefer something like this:
do_something( actors[0], actors[1], actors[2], actors[3] );
for (int i = 4; i < numActors; ++i) {
do_something_else( actors );
}