unary plus, you can read more here https://stackoverflow.com/questions/17106681/parseint-vs-unary-plus-when-to-use-which

Literally, the exact same words that came out of my mouth.

see above

I think common users are more likely to rank a kata based on raw feeling of difficulty, while power users are more likely to vote based on criteria. Power users know what the criteria mean and have been around long enough to be familiar with them. The same might be true for some common users, but not all. So, when I rank (which doesn't happen as often as it should), I use the criteria to guide me, checking myself against the power users; and for edge cases that could go either way, I tend toward the common users.

I see your point, but when I rank during an approval I tend to, conversely, consider the common users more, as power users might be biased, having a "too easy" notch well below most other devs and engineers.

I hear what you're saying and I did ponder the ranking for some time before I gave it a 7KYU :-)

The definitions are as follows

7 Kyu

7 kyu kata represent a beginner programming level. At this level the kata will generally challenge users on their core language and API reference knowledge. Tasks such as:

Iterating arrays and returning a subset of values
Basic data type manipulations
Basic functional or object-oriented concepts
Basic Regular Expressions

6 Kyu

6 kyu kata represent a novice programming level. At this level the kata will start to include more advanced algorithmic challenges and more complex language features. It includes:

Complex language features (closures, scopes, monads, etc)
Complex OOP/Functional concepts
Basic Design Patterns
Complex Regular Expressions

I took into concideration what @Blind4Basic said about the performance and if you take a look at my solution (Ruby) you can see that I only use basic language features and no performance. Also @GiacomoSorbi mentioned that he was going to make a performance version of this kata which will increase the ranking of the new kata.

The average ranking for this kata was 6KYU but the average ranking by Power Users (users with lots of exerience with this site) gave it a 7KYU this is why I finally ranked it as a 7 :-)

If the general census from users is that it should be ranked as a 6, then I'd be more than happy to change it :-)

I gave it a 6 :-)

Tell the rankers, not me ;)