Slashdot Mirror
Followup On Java As "Damaging" To Students
hedley writes "A prior article on the damage Java does to CS education was discussed here recently. There was substantial feedback and the mailbox of one of the authors, Prof Dewar, also has been filled with mainly positive responses. In this followup to the article, Prof. Dewar clarifies his position on Java. In his view the core of the problem is universities 'dumbing down programs, hoping to make them more accessible and popular. Aspects of curriculum that are too demanding, or perceived as tedious, are downplayed in favor of simplified material that attracts a larger enrollment.'"
I'm in one of Canada's biggest CS schools, and though I'm in engineering, I really do feel sorry for them. Many of the toughest courses in that program are now optional, and one can cruise by and get a degree only knowing the most basic algorithms (quick sort?) and data structures. Naturally, the only people who take the original challenging courses are the alpha geeks who live for that kind of stuff anyway.
Meanwhile people come out of the doors of this school knowing only Java and .NET, and then complain that the world of programming was not as interesting as promised. Hmm.
On the other hand, I'm in an electrical engineering-like program, and we only deal with assembly, C, and maybe C++ on the odd occasion. I love it. IMHO any self respecting programmer needs to at least KNOW how to operate close to the metal, if only so it makes them a better coder at the higher levels.
I was taught how to handle pointers in QBASIC when I was in junior high.
The assignment was to implement a linked list. The instructor had us initialize an array which represented our memory block. The program then had to perform all the standard linked list operations, handling memory allocation and all that crap.
The choice of language may seem odd, but consider that QBASIC is what we had available. All our DOS computers already had QBASIC on them, and we could use it without having to shell out the big bucks for a C/C++ compiler (none of us was aware of DJGPP at the time, though I later used DJGPP to teach myself C++).
Now, if the problem is that students aren't being taught memory management, then that is obviously a problem, no matter what language is being used.
If you had super powers, would you use them for good, or for awesome?
I am one of those "fake" programmers building web and database apps with VB, ASP, JavaScript and the like. FWIW, have I never referred to myself as a "programmer" of any type, as I suck at math and have no formal training in CS. I just use tools that are easily accessible and best allow me to make myself a more valuable to my employers. Every once and a while I get the bug to read-up on something like C++ or even Assembly but it is soon obvious that these are not relevant to the problems I was trying to solve and I would rather do other things with my time.
The author strikes me as a typical "You kids have it easy -- I used to walk to school in the snow uphill both ways" type who resents the fact that his formative experiences are no longer relevant. How does the field progress if everyone is forced to retrace the same steps from the same start point? That is not to say that his specific concerns are invalid. But it seems to me that the evolving state of software requires a broader range of programmers. If Java introduces people who will never become excellent programmers to programming concepts, why is that a bad thing? There are many roles to play, and hardcore math geeks can't fill them all. Rather than chase everyone else out of the field, perhaps the next step is for schools to adpot a more sophisitcated approach to organizing their CS programs.
I see an advantage in distributing programming skills as widely as possible. Being able to create my own tools makes me much more useful to my employers, and the combination of business knowledge and programming knowledge make my overall skillset more difficult to outsource. Win-win. Even a programmer who "only" knows Java is infinitely more useful to society than a technophobe with a Liberal Arts degree (speaking as a non-technophobe with a Liberal Arts degree).
What were they?
Java solved these problems by looking to the most advanced technology in the industry, and packaging it in a way that was so straightforward and simple that it was the DEFINITION of the KISS principle. What were these wonders?
The productivity gains from these changes were astounding! But it didn't completely replace low-level coding in C/C++. Why? Because sometimes you needed to get down to the metal to make things work well.
Today, the JVMs have been optimized like crazy. They can automatically make a program run faster as long as you know how to work with the GC and data structures that it provides. If you fight it, your performance drops like a rock. If you don't know how to use it, you might as well be fighting it.
Yet how is a student supposed to know what the JVM is doing if he's never had to scrounge for bytes? If he's never had a practical need for a linked list? If he's never had to implement memory management? If he doesn't have the first clue how to balance a tree? If he can't understand how a garbage collector works? If he doesn't know what a circular reference is? If he can't explain what a pointer is and how a reference is related but different to a pointer? If he doesn't even know what "Turing Complete*" means?
Java as a tool can be sharper than any other blade. But it is a double-edged blade. If you swing it wildly, it will cut you. If you wield it like a master, it will allow you to attack your problems with precision and vigor.
As a side note, I wonder if it isn't time to start teaching students using virtual machines that replicate the limited environments of yesteryear? Not only would it force them into solving the low-level problems, but it would also provide them with the ability to visually inspect the state of the virtual processor, memory, and I/O. Much better than a simple stack-trace, wouldn't you say?
*Imagine a computer scientist with no knowledge of what "Turing Complete" means being assigned to design the future of computers. Frightening concept? Very. Perhaps Quantum Computing would already be here if we had a greater number of qualified scientists?
Javascript + Nintendo DSi = DSiCade
There is nothing that makes Java unsuitable for learning algorithms and data structures. The fact that Java comes with a set of prefabricated components does not mean that it can not be used for such a task. C++ and Java have exactly the same algorithmic issues, because Java, despite what others may have said, is essentially C++ with a garbage collector and all objects allocatable on the heap. Java also has pointers; it's not possible to say "I know Java but not pointers", because even the language itself admits it has pointers: it throws a null pointer exception when a pointer is null. There is also a little bit of memory management thrown in, in the sense that pointers must be nullified as soon as possible so as that the collector clears unused objects.
Java has some advantages over C++ that are important for teaching programming: it has an established set of patterns that all libraries use, whereas in C++ there is no discipline, anyone can make anything in any way possible. For example, many Java libraries use the listener pattern.
Java treats exceptions correctly (despite of being boring to having to program around them), where is in C++ exceptions are not used, although they are available a long time now.
Another advantage of Java is its typing system, which covers a great spectrum of typing systems: it is strong, it is static, but it is also a little bit of dynamic when one uses interfaces. It's very important, and since OO is dominant these years and for the future, it's a very important aspect and Java is the best environment to teach and experiment on these issues.
Java is also suitable for teaching concurrent programming, due to its support for threads. In fact, a Swing programmer must already know threads, because a Swing application is already threaded right from the start.
So what is left? low-level system calls and system libraries are operating system-specific tasks, and have no place in the programming course, unless the course is about kernel programming. Manual memory management is a C/C++ specific task, so unless someone is required to program in those languages, it's not a requirement for today's majority of applications.
So, in conclusion, I believe that there is nothing wrong with teaching Java. I think the core of the problem is that they don't teach the fundamentals of programming (algorithms and data structures), not the language itself.