s****l
发帖数: 41 | 1 #include
class A
{
public:
A(int n = 2) : m_i(n) { }
~A() { std::cout << m_i; }
protected:
int m_i;
};
class B
: public A
{
public:
B(int n) : m_x(m_i + 1) , m_a(n) { }
public:
~B()
{
std::cout << m_i;
--m_i;
}
private:
A m_x;
A m_a;
};
int main()
{
{ B b(5); }
std::cout << std::endl;
return 0;
}
为什么输出为 2531？ |
l*********s
发帖数: 5409 | 2 sequence of detor calling is the reverse of sequence of ctor calling. ctor
calling follows the order first base class, then the member variables |
p*a
发帖数: 592 | 3 先call B的destructor，打印2，然后call m_a的，打印5，然后call m_x的，打印3，
最后call B的父亲A的dtor，打印1，因为m_i已经被--过了。
【在 s****l 的大作中提到】
: #include
: class A
: {
: public:
: A(int n = 2) : m_i(n) { }
: ~A() { std::cout << m_i; }
: protected:
: int m_i;
: };
: class B
|
