what is the difference between: main( ),int main( ),void main( ),main void( ),void main(void),into main(void) ?

Answer 1

Main() and main void() are not valid statements.
int main() returns an integer value from main to os.
Void main() returns nothing from the main to os.
void main(void) doesnt take any arguments and returns nothing back to the os.
int main(void) doesnt take any arguments but returns a integer back to the os

Answer 2

According to c++11 ISO main must be type integer and can accept two values or no values. The permitted definitions are 1) int main (void) {} or 2) int main (int argc, char *argv []){}