Why use in c programming void main?

Answer 1

The compiler needs to know where a program starts. This is called the entry point of a program. The main function is just the standard way of denoting where the entry point of your program is.

Answer 2

Every program starts with the main function because that is how the run-time library startup routines work. It is the established convention. There has to be some entry point, otherwise the program could not do anything, and main() is the defined entry point.

That is, main() is the entry point after run-time library startup.

Note: Not the program starts with main, only its execution. In the source the main can be at the very end of the file.

Answer 3

The use of void main in C (or C++) is deprecated because it is expected that the main function of a program must return an int that reflects the results of the execution of that run. By convention, 0 means success, and anything else means failure. The actual value of the return value is by agreement with the programmer and the invoking program, but the main point here is that main should return an int, not a void.

Answer 4

The global main function provides the entry point of an application, without which our application would be invalid. We can actually have as many main functions as we want, however we can only have one global main function. The global main function has two common signatures:

int main (void);

int main (char* argv[], int argc);

The second version is used when a program expects command-line arguments. However, even if our program doesn't use any arguments, it is is best to use the second version to obtain the fully-qualified path to the executable from the command-line processor. The argument names are conventional; we can use any names we wish, but it's best to use the conventional names for consistency:

argv: null-terminated array of pointers to null-terminated strings

argc: count of arguments in the array

argv[0] always refers to the fully-qualified path to the executable, thus argc is always at least 1. argv[argc] is always nullptr (the array's null-terminator).

It is generally useful for the main function to iterate over the array and create a vector of strings which can then be more easily passed to a process function to decide what actions (if any) to take. This helps keep our main function as brief as possible, even with the inclusion of a catch-all exception handler:

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

std::vector<std::string> command {};

for (int i=0; i<argc; ++i) command.push_back (std::string{argv[i]});

try {

return process (command);

}

catch (...) {

// catch any and all exceptions here...

}

}

Answer 5

A c program doesn't begins with main function, but during execution of that program execution begin with the first statement of the main function.

Answer 6

The global main function serves as the entry point of the application. When an application is executed, all static objects are initialised first and then the global main function is executed.

Answer 7

That's a convenient way to specify a program's starting point.