Should have explain better on this seriously, "come before" can be understand as stand before as place in the string, so "2000" start with "2" and "11" start with "1", if sort by string then become "11 2000"

I agree. Not worded very well. I interpreted to be which string came first in the input, not alphanumerically as Lazy Wolf states correctly.

me too. the same weight ,how to order it?

I have to agree, this was one of the most poorly explained Kata's :( i parsed the string as an integer to compare.

Look also at how one compares (puts in order) strings.

You wrote yourself:

Okay, but the instructions are: "When two numbers have the same "weight", let us class them as if they were strings"

As a string (and also as a number) "11" comes before "2000".

But you should have maybe a look at what strings are in the language you are using at CW (Ruby, Python, ..., ?).

Is "1"before of after "2" as string? "11" < "2000" => true, no?

There are no error in the test.