I feel better about my newbienishneess now!

Why not use a switch statement instead of so many ifs?

It's easy enough to test this. ;-)

The answer is no, it returns false, which is incorrect. In fact, my answer fails most cases, except, amazingly, the test cases.

You should recommend some new test cases to invalidate answers such as mine.

Good find!

In the case compareVersions(10,9.4) , will this solution return true?

There was a mistake in the tests. Acording with description ("You can use any number of summands positive integers and these can be repeated as often as you like."):

sum(0); // 0 <- There is no way to achieve this result with positive numbers.
sum(-1); // 0