There are 23 rotations of string 'bsjq'. Array ["bsjq", "qbsj", "sjqb", "twZNsslC", "jqbs"], wich contain only 5 elements can't include all 23 rotations. I can't anderstand why this case return true.

You could use console.log to measure whether each thing you do is having its desired effect.
There's no reason to stop at saying that the overall thing doesn't work, it is made out of smaller parts, you can test those smaller parts individually.

When posting such a question, please mention your language, post your code ( properly marked up and spoilered ), and include input and actual and expected output of a test you're failing. Help us help you!

That said, you might be forgetting a return statement.

Thank you very much!! I used the wrong function's name.

The only way I get that error is if you have a typo in the function's name, but I've copied/pasted what you wrote there and it's ok. Click reset, and do the same I did.

Dear Chrono, I didn't catch how to define function. I had 'multiplyAll is not defined'. Help me, please.

It worked for me, and remember to mark your post as having spoiler content next time.

Test OK. Random test is not.((( What can be the reason of undefined? Expected: false, instead got: undefined

Help me please. How to use RgExp with cicle for? Before cicle s is array of strings like [ 't', 'o', 'u', 'r' ]. I have tried for...{ if(s[i] === /[aeiouy]/g) {s.splice (i, 1)}}. RegExp does not work. Where is mistake?

You are supposed return the answer, you're logging it in console.