C vs Java

[Venu Chakravorty]

What are the things that can be done in C and not in Java. Let's keep aside JNI.

Thanks and regards,
venu

[David Newton]

Depends on the Java implementation.

[Rob Spoor]

Pointer arithmetic. Returning multiple values from a method (through pointer variables). Creating objects (actually structs) on the stack instead of on the heap. Manually cleaning up memory*. Communicating directly with the OS and hardware platform.


* my onetime real-time Java project could really have used this. With little strain it ran for a few minutes, then crashed with an OutOfMemoryError because the garbage collection could not run.

[Gert Jan Kruizinga]

Yes, pointer math (or magic) is what i miss the most.

[Henry Wong]

Gert Jan Kruizinga wrote:Yes, pointer math (or magic) is what i miss the most.

I used to miss it (in Java), but not anymore... In fact, I am more used to not using it, that I try not to do pointer arithmetic, even when I am working in C / C++.

Henry

[Rob Spoor]

Oh come on... you must miss writing neat little functions like this:

char* strcpy(char* dest, const char* src)
{
    while (*dest++ = *src++); 
    return dest;
}

You just gotta love that!

[Pat Farrell]

Rob Prime wrote:

char* strcpy(char* dest, const char* src)
{
    while (*dest++ = *src++); 
    return dest;
}

You just gotta love that!

Nope, I never loved that, even when I was writing PDP-11 assembler code. Note the PDP-11 and later Vax has single hardware instructions to implement the critical

*dest++ = *src++ 

construct.

Using null delimited strings has been a huge source of evil bugs over the decades. And of course, it fails totally with non-ASCII data. The world is bigger than just the folks who speak English.

[David Newton]

I miss it, although I still do enough embedded work that I don't have to miss it for very long :) What I *really* miss is making dynamic, extensible language implementations in resource-constrained systems a la Piumarta-style stuff, which makes use of pointer arithmetic. Quite enjoyable.

[Gert Jan Kruizinga]

Yes Rob Prime, that is what i miss, and it starts getting interesting if *dest points to the i/o space of an device.

[Campbell Ritchie]

Moving thread as not a "beginning Java" question.

[Campbell Ritchie]

It's even more fun using FORTH the way I do it where I have to do pointer arithmetic directly on the stack!

[David Newton]

Everything is more fun in Forth :)

If there's one language I truly miss working with, it's Forth, although I may take up Factor again. On an only vaguely-related note, I did get to work with actual PostScript for awhile when working at a high-speed printer manufacturer. In addition to the language, we also had really fast cameras to take pictures of how paper moved through the printer--before then I had never really given such thing any thought: paper physics. Crazy stuff.

[Campbell Ritchie]

David Newton wrote:Everything is more fun in Forth . . .

Even the segmentation errors when you can't see where they happened.