Is it true that computer viruses only effect PC's ?

A friend once told me , to the best of his knowledge, that computer viruses only effect PC's on not Apples, or Macs. Is this true ?

Is it true that computer viruses only effect PC's ?triumph

No. There are more viruses designed for PCs simply because there are more PCs; but, there are viruses that attack Macs and Apples.

Is it true that computer viruses only effect PC's ?worms

No, It's not true, the only reason viruses attack PC's more often is because PC's have been out for so long, and hackers have had a while to try and figure out the system, and how to bypass it, and install viruses. In 1-2 years the Mac will be having the same problems.

Viruses attack Mac's as well.

Also another reason Mac's don't get attacked as much is because nearly 75% of computer owners own Window's PC's, so obviously if you're going to attack a computer you'd take the one with the majority of users. But people are finding out how to attack Mac's now, because people are buying them now.

EDIT: Take it from a computer expert, there are no advantages of buying a Mac, unless you are very computer-illiterate. All it does is look better, and get less viruses FOR NOW. Anyone can program the Mac design onto a Windows computer for free, I've done it myself. Mac users mistake my computer for a Mac. PC's are more customizable, and have many more programs, and better customer support, as well as much cheaper. Just spend a little time exploring the PC, and you can learn a lot, and love it.
Virus are aimed at different things, yes normal Windows but there are Virus for APPLE for Phones too