Computer Science (or "Information Technology" as it's officially called) is an elective at school that students can take starting at the Grade 9 level. Students start out learning Python as their first language and learn C++ after two years.

I would guess 100-200 students take the course in total out of about 1800 students in the school. Students receive a very comprehensive education in the field and are encouraged to work on their own projects at the same time (e.g. I've done a lot of work in node.js, which isn't at all taught in the CS curriculum). Personally I've found that my teacher has given me the original knowledge of programming and from there I mainly was able to develop my knowledge on my own time as well as through the course.

Edit: more technical details: One can take an IDS (independent study) course in Computer Science their final year if they wish. Here you get to work on your own programming projects.