学步园

29.   说出下面的运行结果

//虚函数动态绑定=>B ，非 A，缺省实参是编译时候确定的=>10 ，非 20 

#include <iostream>
using namespace std;
class A
{
	public:
		virtual void Fun(int number = 10)
		{
			std::cout << "A::Fun with number " << number<<endl;
		}
};
class B: public A
{
	public:
		virtual void Fun(int number = 20)
		{
			std::cout << "B::Fun with number " << number<<endl;
		}
};
int main()
{ 
	B b;
	A &a = b;
	a.Fun();
	return 0;
}

输出：B::Fun with number 10