this is definitely best practice

Nice

I suggest removing all references to PHP since beginners (like myself) do not know that language. I only got it right after educating myself by perusing most of the comments down below... and solved it after making a lucky guess on the syntax during programming. (I only know Ruby, by the way).

This kata can achieve the same educational outcomes that you intended for beginner warriors without including PHP, so there is no need to include it. And yes, for this kata without PHP, I agree with all warriors' recommendations for a 7 kyu ranking.

However, if you must keep the PHP, ranking should be higher.

Thanks :)

Thanks! :)

This is actually one of the fastest solutions, according to my profiling of most of the solutions here. Nice!

For all of you who do not want to write test cases, copy and paste the following into your test-case-screen. These worked for me and are based mostly on info from the instructions:

describe "Solution" do
it "should test for something" do
Test.assert_equals(domain_name("http://github.com/carbonfive/raygun"), "github", "acerroblanco's test case #1")
Test.assert_equals(domain_name("http://www.zombie-bites.com"), "zombie-bites", "acerroblanco's test case #2")
Test.assert_equals(domain_name("https://www.cnet.com"), "cnet", "acerroblanco's test case #3")
Test.assert_equals(domain_name("www.xakep.ru"), "xakep", "acerroblanco's test case #4")
end
end

Thanks! It works nows. I appreciate your help :)

remove the def show_sequence(n) at the top, and one of the ends at the bottom.

Your show_sequence function is inside the self.show_sequence method. The method is called but the inner function is not.