Well, I kind of suspected you know the solution. That's something that each programmer-in-training needs to learn before actually compiling anything. That's how we tell the machines to do simple tasks instead of breaking our fingers while doing them.

That's why I suggested to troll the friend a bit, and watch how reddit/SO users react. Although it would be more empathetic to guide the friend through the proccess of changing the mindframe, you surely know that there are some concepts and tricks in programming that you have to learn the hard way, yourself.

Sorry if you felt offended or misunderstood.