Recently, I am seeing a lot of people use void main() instead of int main. Is this a good practice? I use int main, isn't that the correct way? Unless, your trying to shut off warnings about main not returning a value. What are the pros/cons? Which is better?
Last edited by Annonymous; 10-20-2011 at 03:00 PM.
I noticed my hand was bleeding. So I chopped my arm off. Hand stopped bleeding, so I know I fixed the problem.I use int main, isn't that the correct way? Unless, your trying to shut off warnings about main not returning a value.
Code://try //{ if (a) do { f( b); } while(1); else do { f(!b); } while(1); //}
How the fvck does that answer my question?
Last edited by Annonymous; 10-20-2011 at 03:00 PM.
It means, you could either bandage your finger (add a return statement), or chop off your hand (use void main).Originally Posted by Annonymous
brewbuck simply related chopping off the hand to void main because it's non-standard. And why use a non-standard construct when there's a perfectly legitimate and easy way to fix it?
Not quite true. If you use void main, you will be in the land of undefined behavior. Some compilers actually make sure to return 0 if you use void main (eg Visual C++) and some will just return whatever happens to be present in the register used for returning variables (typically eax; eg, GCC).
Though you are correct in that it will have undefined behavior.
Last edited by Elysia; 10-20-2011 at 03:07 PM.
Ok, if this is not good practice. Why are people using it? Any ideas? Could the colleges possibly be teaching this practice?
Cluelessness is one factor.
Another is dumb colleges teaching it.
Yet another is dumb books teaching it.
And yes, even tutorials.
Even MSDN, Microsoft's great developer network still have articles that uses void main.
And, in fact, I've even seen some Microsoft devs use it in their presentations on the recent build conference.
Lastly, there are some non-standard conforming devices (particularly embedded devices) that simply use void main (usually because int main makes no sense).
Yes!Could the colleges possibly be teaching this practice?
Some implementations allowed it before there was a standard. Some implementations (e.g. Turbo C) still allowed it even after the standard. When you see it on this board, it's often from a Turbo C user. Many/most/all of India's universities still teach on the very outdated Turbo C, and many of them come here for help, hence all the instances of void main.
Note, in unhosted environments like embedded systems (one's without a "typical" OS), the standard does not require int main, since there is no environment to return a value to. Thus, an embedded compiler may allow or even require void main, though personally I have not seen such an implementation. We occasionally see void main used on embedded projects here, though it's much less common than the cancerous Turbo C.
I am not aware of any standard in either C or C++ that allows the use of void main (though technically there was a possibility in C90).
Many embedded compilers are often non-standard.
Yes, they are... Many schools, especially in India, are hopelessly out of date; still teaching with Turbo C (a 16 bit compiler who's output won't even ruin on 64 bit windows) and course designs that date back to MS-DOS.
LOL - "ruin" - fantastic typo - and yet so apt.
> It's used in batch files and shell scripts, it's used when one program launches a child program and so on.
Yes indeed.
Long ago, I found a fantastic little utility for a job I was doing that was rendered almost completely useless because the exit status was garbage.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
No!Is this a good practice?
Absolutely.I use int main, isn't that the correct way?
One is non-standard (void). The other is standard.What are the pros/cons?
Follow the standard.Which is better?
Jim
Operating systems will sometimes make use of the return value when your program ends and you return to the OS. If you don't return anything, the "return value" will be garbage and the results will be unexpected and mysterious.
Code:while(!asleep) { sheep++; }
Since this is such a common issue, we actually have a great link explaining all about it: Cprogramming.com FAQ > main() / void main() / int main() / int main(void) / int main(int argc, char *argv[]). At the end of that article, it links to a great page. I'll repost the link here, just so you don't miss it: void main(void) - the Wrong Thing.
Thank you Anduril462
Yes many institutions of "higher learning" teach this bad programing practice, using outdated, pre-standard compilers. Many of the universities in India are a prime example.Ok, if this is not good practice. Why are people using it? Any ideas? Could the colleges possibly be teaching this practice?
Jim
