What a Seasoned Professional has to Learn from Scratch

Passing parameters (sometimes called arguments):  In mathematics, this would resemble in many ways a function call.  I'll try to do a Scratch-like example:

Let's say we had a project with some fish in an aquarium and we wanted to tell them to change their color.  In Scratch now, we could make up broadcast messages such as "Fish turn green", "Fish turn red", "Fish turn blue", etc.  We'd have a different broadcast message for each color.  If there were lots of colors that we wanted to have the fish become, we'd have a lot of messages.  And if there was a situation where we couldn't anticipate what color we wanted for the fish, we'd be in trouble because we can't just define a new broadcast message "on the fly".

But both of these problems would go away if we could attach "parameters" to a broadcast message.  I'm inventing syntax here, but for instance perhaps Scratch could let us say: Broadcast "Fish change color" with "green" or Broadcast "Fish change color" with "blue".  or even better Broadcast "Fish change color" with "Variable: Favorite Color".  Then we need only one broadcast message and we are able to create variations of the same message by using parameters.

Now you can simulate this to a large degree now by having a variable that hold the new fish color and making the broadcast message say:  "Fish, look at the new fish color now".  That has much the same effect, but it is a two step process and in some ways is harder to follow in the code.

Creating objects "on the fly":  Let's say that we made a project where we asked the player "How many lightning bugs would you like to see flying around randomly?".  They'd say some number and then what would we do?  Well, if we had made enough lighting bug sprites to match their largest possible number, we could just "show" the appropriate number and "hide" the others.  But that is sort of a pain because we have to make a large number of sprites and set up a script for each one.  It would be much easier if we could just say, in effect, "Clone a new lighting bug sprite just like (the original Sprite name goes here)."  In object-oriented programming, we would call this an "instance" of the "lightning bug sprite object".  So now the number of sprites that we have on the screen is no longer limited to the number that we define before running our project.

I do lots and lots and lots of JavaScript at my "real" job.  I also do quite a bit of Java and C#, too.

Java and C# are enough alike that if you write Java code with a "C"-like syntax, it will probably become C#, more or less.  (Sure, I'm skipping over some differences such as delegates and anonymous functions, etc.)

Javascript (more properly ECMAScript these days) is very different in practice than either of those.  It's more interpretive and less strongly-typed.  Javascript is easy to write and hard to debug, which I think is the opposite of what beginners need (and even often us pros, I think).  In my opinion, there aren't any really effective debuggers for Javascript.  The closest ones are Firebug and MyEclipse, but it is still not like the relevant, right-on-top-of-it, debugging of Visual Studio for C# and Visual Basic or Eclipse for Java.

I'm sure there are several interesting environments around like Scala and the ones you mention that I haven't really checked out.  But if you want to have fun learning programming with an accepted "professional" langauge, I think one viable possibility is to use Microsoft's C#/XNA.  It's free and you can even run your code on the XBox (with XBox membership cost).  There's even a community.  Tutorials abound.  Just Google a phrase like:  C# XNA tutorial .  Some are for those with experience.  Some video tutorials are for beginners and most are oriented around making games.  And if you don't like being in the Microsoft world, remember that nearly all of your C# skills transfer very well to Java.  That said, C#/XNA is an adventure more for an interested high-schooler than the casual 2nd-5th grade Scratchers that I teach.

Regarding an earlier discussion, I personally don't worry much about whether one learns recursion, but I think that object-oriented programming is an important concept.  Some of that comes through in Scratch, partly from its SmallTalk heritage.  I miss things like creating objects on the fly more than I miss recursion.  I even miss such niceties as passing parameters or being able to direct a "broadcast" to a more specific audience of listeners.  I think that these latter two features, though, could be added to Scratch in an optional, structured way that would not hurt the simplicity and clarity of Scratch as we know it.

To add to Toby's list, I'd suggest looking at Greenfoot. It's a Java programming environment that provides a framework with a stage and sprites ("actors") so you can quickly build interactive games or stories like those can build in Scratch. But the code is real Java -- complex syntax and all -- and you can use all the Java API's.

Another cool language is JavaScript. It's interactive, fairly simple, and it's built into most browsers. I haven't looked for any step-by-step tutorials, but I'm sure they must exist.

By the way, Scratch *is* programming. While Scratch doesn't require that you master the syntax of a text-based programming language, the program logic is exactly the same as C, Java, Python. In fact, Scratch is used in courses at Harvard, The College of New Jersey, and elsewhere as an introduction to those languages. From all reports, Scratch works very well in these courses because its constructs *are* so similar to other languages.

-- John