overload与overwrite
class base
{
public:
void sayhello(int n)
{
std::cout<<n<<std::endl;
}
};
class sub :
public base
{
public:
void sayhello(char *msg)
{
std::cout<<msg<<std::endl;
}
void sayhello()
{
std::cout<<"null"<<std::endl;
}
};