I am reading on this site and they have this code
HWND parent = NULLCode:HWND Create(HINSTANCE hinst, LPCTSTR clsname, LPCTSTR wndname, HWND parent = NULL, DWORD dStyle = WS_OVERLAPPEDWINDOW, int x = CW_USEDEFAULT, int y = CW_USEDEFAULT, int width = 450, int height = 380);
? you can assign a variable in the functions declaration? How does this work?