Standard C++ requires main to have an int return value, which indicates the normal end of the program. int main() corresponds to return 1; (return an integer value)

But in C, void main( ) that is, main() has no return value

Although the C++ standard does not allow main to be void, some compilers such as VC6 allow main to be void.

The header file declares as #include(The .h header file in C++ supports C and is non-templated)

If you are learning C++, it is better to write int main()