Archief - C++: vraagje over basiscode console application

Can I write "void main()"?

The definition

Code:

void main() { /* ... */ }

is not and never has been C++, nor has it even been C. See the ISO C++ standard 3.6.1[2] or the ISO C standard 5.1.2.2.1. A conforming implementation accepts

Code:

int main() { /* ... */ }

and

Code:

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

A conforming implementation may provide more versions of main(), but they must all have return type int. The int returned by main() is a way for a program to return a value to "the system" that invokes it. On systems that doesn't provide such a facility the return value is ignored, but that doesn't make "void main()" legal C++ or legal C. Even if your compiler accepts "void main()" avoid it, or risk being considered ignorant by C and C++ programmers.

In C++, main() need not contain an explicit return statement. In that case, the value returned is 0, meaning successful execution. For example:

Code:

#include<iostream>

int main()
{
	std::cout << "This program returns the integer value 0\n";
}

Note also that neither ISO C++ nor C99 allows you to leave the type out of a declaration. That is, in contrast to C89 and ARM C++ ,"int" is not assumed where a type is missing in a declaration. Consequently:

Code:

#include<iostream>

main() { /* ... */ }

is an error because the return type of main() is missing.

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killgore zei:

en dat eerste is fout afaik in C++ standaard, er MOET een return staan .

btw: er zijn

Code:

 tags[/QUOTE]Niet per se. Als er geen return statement staat in de main() dan gaat die standaard zelf een integer teruggeven. Maar alleen in de main(), dit wordt niet gedaan in andere functies.

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zero roofer zei:

lol in dat geval zit ik op een kakschool... mij hebben ze van het begin erin getimmerd dat uwe main "void main()" is

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