Is it better to use C void arguments "void foo(void)" or not "void foo()"?

Question

What is better: `void foo()` or `void foo(void)`?With void it looks ugly and inconsistent, but I've been told that it is good. Is this true?Edit: I know some old compilers do weird things, but if I'm using just GCC, is `void foo()` Ok? Will `foo(bar);` then be accepted?

Answer 1

// in standard C, you used to write (void) if there were no args

// but most compilers follow the C99 (and the C11) standard

// and no longer require that

#include <stdio.h>

void foo(void) { // you can now say void foo()

printf("Function taking no arguments and returning void\n");

}

// in C++, you don't have to write (void) if there are no args

#include <iostream>

void foo() { // you can always say this in C++

std::cout << "Function taking no arguments and returning void\n";

}

// Note, as an aside, some textbooks (even Kernighan and Ritchie)

// showed calling main as

int main() {

// ...

}

// in most cases, you will want to process command line arguments,

// something like this

int main(int argc, const char* argv[]) {

// argc is the number of command line arguments

// argv[] contains pointers to the command line arguments

// first command line argument is the name of the program

if (argc != 2) { // std::cerr is the error stream

std::cerr << "Usage: ./program_name filename\n";

exit(1);

}

const std::string filename = argv[1];

// ... use the filename to process

// ... more code here

return 0;

}