The computer only knows where they go because the rest of the code already has the parens. Having the parens has advantages, like everything being explicitly d

The computer only knows where they go because the rest of the code already has the parens. Having the parens has advantages, like everything being explicitly delimited, which makes it really unlikely that you'll insert some code that you thought was part of a block, but really wasn't (think one-armed if without braces in C-like languages). It also makes it easy to have your editor help you navigate your code. Being able to jump around expressions conveniently can really speed things up.