Master Object Oriented Programming. Smalltalk’s Big Secret: Turtles!

What the heck are turtles anyway? In this lesson, I’ll show you how Squeak Smalltalk’s turtles can really help you get to grips with OOP (object oriented programming). They let you control obvjects by sending one or more messages to them. And the end result - you can draw pictures on screen interactively.
In this lesson, I explain: cascading messages, turtle graphics, drawing with pens and creating both local and global variables. As always, you should download a free copy of Squeak Smalltalk and a free copy of the Smalltalk/V Tutorial so that you can follow along with this course.
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• Object Oriented Progra...
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WHO IS HUW COLLINGBOURNE?
I’ve been programming since the early 1980s. I’ve written wrote programming columns on Java, C#, Delphi and other languages for “PC Plus Magazine”, “Computer Shopper” and numerous other UK magazines. I wrote the cult adventure game, The Golden Wombat Of Destiny, I have developed programming tools with SapphireSteel Software and I have written programming books published by Dark Neon and No Starch Press. These include books on programming C, C#, Java, Ruby, Delphi and Object Pascal, pointers, recursion and programming adventure games.
All my books can be found on Amazon.
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[@mtin79]

Would have needed this 20 years ago. Especially smalltalk / squeak 🐭

[@BryanChance]

I like these smalltalk tutorials and the C# programming. Thank you!

[@LearnWithHuw]

Many thanks.

[@TalhaAzim]

Hi Huw, thanks for working on these tutorials! I've been curious about this for a while but documentation and tutorials are tricky. I know this is an extremely random and strange ask, but do you by any chance know how to connect with Dr. Alan Kay? I'm greatly interested in sharing some ideas with him and getting his advice. Like I said, random and strange.

[@LearnWithHuw]

Alan Kay is very active on Quora. If you have any questions, you could try posting them there. www.quora.com/profile/Alan-Kay-11 There are also some contact details on the UCLA site. I won't post those here but you can search and give them a try if you like.

[@cffinch44]

Your code draws in a other Workspace window where mine draws on the main HomeProject window background. This was frustrating me as my Workspace windows placement covered it so I could not see it. I got no erros but it seemed as if the code would not run. Maybe slightly more detail about how your image is setup is needed so our results look like yours. Also it woudl be nice to see how you use the .st files. I presume you wrtie the code into a .st file using your deitor of chouce and then open it with Squeak. Maybe this is not directly pertinent to OOP but if those watching experience thigns differently than they see on the screen it may cause some frustraioin and even abandonment of further attempts. Simply a suggestion.

[@LearnWithHuw]

I wrote the code in Squeak. Some code I imported from the old Smalltalk/V files (and then edited in Squeak). The drawing is on the screen in some examples but may appear to be on an underlying Workspace window (for ease of viewing). I have only used some very basic graphics here since I just want to use the Smalltalk/V examples to illustrate features such as blocks and loops rather than explore the more powerful graphics of Squeak.