Hi, TIG!
Thank you very much for your detailed answer, it is very usefull for me because I'm just a beginner in Ruby.
I'm sorry for bad pics. I post new

But... about this problem. I just copy code from this book
Automatic SketchUp Creating 3-D Models in Ruby by Matthew Scarpino 2010
It uses SketchUp 7.1 application programming interface (API)

for count1 in 0..5 print count1, " " end

This code doesn't work in Sketchup 6, Sketchup 8, Sketchup 8 PRO. But it works in Sketchup 2015PRO...

Hello!
I'm new here, I'm new in Sketchup, I'm new in Ruby... But I'm not new in programming.
So, I have one maybe too stupid question.
I'm trying to use iterators like 'for in', until and .each. But they don't work! I think this is simpliest things in any programming language... and they work in all languages I use...
What's wrong with my Sketchup Ruby?
I use Sketchup 8 free version