thank you :)

Thanks :)
When i created it i suggest to be 6kyu, but moderator (or voting people, i don't know exacly how it works) change it to 7.

Didn't you miss 0 in split part?

@lekowan
Test pin.split(/123456789/).join('') with diferent values for pin and see what it returns and if pin.length is 4, it isn't 6 and viceversa, so your code would return false in both cases.

Talk about over complicating it. It is only a 7 kyu. use a simple regexp. It is a one liner

I agree. It would make sense to be that, but javascript numbers are wierd sometimes. MDN talks about that a little here https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript#Numbers.

Can you please give a little more info? Why can't the kata be solved with 0.28000000000000025? I just tried the JS version out and everything looks good.

P.S. You aren't going to return an array. You will return a string. For example:

expandedForm(0.28000000000000025); // should return '2/10 + 8/100 + 2/10000000000000000 + 5/100000000000000000'