(C) main

The function main() is the entry point of your program.

There are two syntaxes:

int main(void) { /* Your code */ }

and

int main(int argc, char* argv[]) { /* Your code */ }

What does this all mean?
int main means that main is a function returning an integer.
(int argc, char* argv[]) means that the function takes two arguments:
int argc: argc is an abbreviation of 'argument count'. It is a (positive) integer. This give you the number of parameters the user entered when starting the program, which equals 1 if he didn't enter parameters.
char* argv[] is an array of pointers to type char (say: 'character pointer', see also char*). In here, all the arguments are stored that the user entered when starting the program. At index 0, the program's name is stored.

You can leave out the arguments of main().

Incorrect/non-standard is [1,2] (although with some compilers it might compile):

void main() //INCORRECT!!!
{
  //Your code
}

Should I use void main() or int main()?

int main() [1-4]

'main' links

Code links

References

1) From Bjarne Stroustrup's homepage (http://www.research.att.com/~bs/bs_faq2.html#void-main) :

The definition
void main() { /* ... */ }
is not and never has been C++, nor has it even been C.

2) From the The alt.comp.lang.learn.c-c++ FAQ: http://ma.rtij.nl/acllc-c++.FAQ.html#q3.4: 3.4 Why does everyone make so much fuss about "void main()"?. Because the return type of the main() function must be int in both C and C++. Anything else is undefined. Bottom line - don't try to start a thread about this in alt.comp.lang.learn.c-c++ as it has already been discussed many, many times and generates more flamage than any other topic.
3) http://c-faq.com/ansi/maindecl.html

last edited (December 22, 2006) by bilderbikkel, Number of views: 1195, Current Rev: 2 (Diff)

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