A programming language that can “compute anything,” for a certain (pretty reasonable) value of “anything.”
Turing completeness is a really low bar to jump for a language, because all you really need is some state (a string of memory) and a way to move around that memory based on its state. Any language with arrays, boolean ops and a goto statement are pretty automatically Turing complete, at least to an approximation (a “true” Turing machine requires infinite memory). Clever folks have shown that you can build Turing complete machines with just about any physical object, too (balls and sticks, water and valves, etc.).
The main reason you’d use a non-Turing-complete language for scripting is if you wanted to allow users to do scripting but limit their power. WoW does this with its in-game macros, which use a very crippled Lua that is not Turing complete (it’s also limited to 255 character scripts).
See http://en.wikipedia.org/wiki/Turing_completeness for more.
gouessej wrote:
[quote]Lots of people here seem to think that concentrating on Java game development is not the best thing to do to become a good game developer
[/quote]
I don’t think that’s what people are saying at all; the OP said "but i want to become a 3d game developer like in gta, spiderman, etc…in gud companies… ", and I think people are just pointing out that Java game development is not going to land you a job doing something like that, so it’s not the best thing to do to start a career in AAA game development.
If coding is just a hobby, then maybe it’s fine to learn one language and stick to it like glue, but if you want to make it a career, familiarizing yourself with several technologies is a no-brainer - it’s better for your employment prospects, it helps you become a better programmer overall (there’s a lot of anecdotal evidence that single-language programmers tend to be worse even in their favorite languages than programmers with more varied experience, esp. when it comes to Just-Java programmers; correlation or causation, I don’t know, but it’s still something to think about…), and there’s not much of a downside.