Entertaining and Interesting example to teach Ruby

I have to take a small introductory talk on ruby tomorrow, I want to avoid going the boring power point presentation way and have a hands on session. The goal would be to introduce ruby to people, just the basic concepts really.

I'm planning to take an example from Why's Poignant Guide, do you know of any interesting example that would captivate the attention of the audience and make it an interesting talk.

EDIT : I'm done with the talk, it went reasonably well, there were about 50 people who turned up, About 10 of them picked up ruby really well. Some complained that I went too fast. All in all I covered the basics of ruby, didn't touch the OO Stuff. As for the examples I gave one in which we could scrape data from our colleg开发者_如何学编程e website using watir-webdriver. Thanks to all for your valuable answers and comments.

Ok, so your audience are not programmers, so there's no point of pointing out Ruby's advantages over other languages. Also, there's no place for advanced topics such as metaprogramming or more serious OO or functional programming.

• What I would try to show them first is irb, how they could evaluate simple mathematical expressions, and show them the concept of variables.
• Strings and string interpolation.
• Loops (10.times{ puts 'Hello world!' }) and branches (if-then-else).
• If you have time, show them arrays (not sure about hashes)

I would also try to squeeze in a simple program in Sinatra as well. Students already know web and you can show "how the web really works" using couple lines of Sinatra code.

Maybe they'd be interested in a bit of web scraping.

My project Easy Roommate parser visits a flat-mate sharing web site, and parses profiles to see which ones are compatible with what you want. My main warning is that my code isn't very good, and if lots of people used it, the web site owners may complain. However, it would be solving a problem that's common to many students.

Another project I did ages ago was Get to philosophy, which tried to work out why, when you click on the first link in each Wikipedia article you come across, you usually end up at Philosophy. Warning: this project is abandoned.

Why's Guide is a little nuts for the average audience, more of a work of art than an educational tool. If you like whimsy, you might want to check out Rails for Zombies.

You could show them how to write programs that can be useful for college students in general. For example, let's say they have to study some chapters of a book for an exam. I have a Python scripts, 30 lines or so, that takes a number of days and a list of tuples representing page ranges, and prints how many pages you need to study each day, and at what page you need to get by the end of each day. For example, if you have to study pages [10,19] and [30,33] over two days, you'd need to get to the end of page 16 on the first day, and to the end of page 33 by the second.

You could show them how to implement this sort of thing with Ruby. It's a bit dry, but very practical.

To show oo stuff (if you want to do) consider showing some automation of the Browser with watir. -> Real oo with real objects all in simple Ruby. Perfect for interesting and lively demos to motivate young people (maybe everybody wants to try it out after the presentation (my experience)).
http://watir.com/examples/

Sonic Pi is a Ruby based SDK and DSL. Its typical usage is in music creation and sound generation (samples and synthesizer sounds). The Sonic Pi website http://sonic-pi.net contains tutorials, which are specifically designed to teach programming from the start. There is even a guide for teachers! Sonic Pi is really entertaining and it gives you immediate sense of achievement.