Roger: If you read far enough down in "perldoc -f split", you'll find that  split " ",$string and  split /\s+/,$string are in nearly equivalent (except in how they treat initial whitespace in $string).

Using a single quoted space character as the split pattern is one of those nifty little bits of perl magic that is meant to save unnecessary typing, giving the same behavior as a bare "split" call with no regex pattern. (But  split / /,$string -- not using quotes -- really does split on every individual space character.)

But I think you're right to suggest that the OP should add the extra parens, to make sure there's no confusion about which args are supposed to go to "split" as opposed to "join".