pb->h(3.14f);
pd->h(3.14f);
}
其中子类Derived中 vitual void f(float x) 是覆盖，而void g(int x) 和void h(float x)都是隐藏。
运行结果：
再看一个例子：
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#include
using namespace std;
class Base
{
public:
virtual void f(int a) {
cout << "virtual Base::f(int a)" << endl;
}
void f(double d) {
cout << "Base::f(double d)" << endl;
}
};
class Derived : public Base
{
public:
void f(double d) {
cout << "Derivd::f(double d)" << endl;
}
};
int main()
{
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Base b;
b.f(5);
b.f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
}
#include
using namespace std;
class Base
{
public:
virtual void f(int a) {
cout << "virtual Base::f(int a)" << endl;
}
void f(double d) {
cout << "Base::f(double d)" << endl;
}
};
class Derived : public Base
{
public:
void f(double d) {
cout << "Derivd::f(double d)" << endl;
}
};
int main()
{
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Base b;
b.f(5);
b.f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
}
其中父类中的void f(double d)隐藏了子类的virtual void f(int a), void f(double d)函数。
所以在主函数中
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Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);只要通过Derived对象或者Derived指针执行f()函数，都只执行void Derived::f(double d)该函数。
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Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);在调用pBase->f(5)时，首先要去pBase类中找到对应需要执行的函数，因为Base类中有两个函数virtual void f(int a) 和 void f(double)重载，因为该实参是5，为int类型，所以要调用virtual void f(int a)函数，因为该f(int a)是一个虚函数，所以再去判断pBase所指向的具体对象，具体对象为Derived子类，再去Derived子类的虚函数表中找到void f(int a)函数。因为Derived子类继承了父类Base的虚函数vitural void f(int a)，所以输出 virtual Base::f(int a);
在调用pBase->f(3.5)时，首先要去pBase类中找到对应需要执行的函数，因为因为Base类中有两个函数virtual void f(int a) 和 void f(double)重载，因为该实参是3.5，为double类，所以要调用void f(double d)函数，因为该函数是一个普通成员函数，故直接输出。 void Base::f(double d);
再举一个例子：
[html]
#include
using namespace std;
class Base
{
public:
virtual void f(int a) {
cout << "virtual Base::f(int a)" << endl;
}
void f(double d) {
cout << "Base::f(double d)" << endl;
}
};
class Derived : public Base
{
public:
void f(int a) {
cout << "virtual Derived::f(int a)" << endl;
}
};
int main()
{
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Base b;
b.f(5);
b.f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
}
#include
using namespace std;
class Base
{
public:
virtual void f(int a) {
cout << "virtual Base::f(int a)" << endl;
}
void f(double d) {
cout << "Base::f(double d)" << endl;
}
};
class Derived : public Base
{
public:
void f(int a) {
cout << "virtual Derived::f(int a)" << endl;
}
};
int main()
{
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Base b;
b.f(5);
b.f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
}
子类Derived中的void f(int a)既覆盖了基类Base的虚函数virtual void f(int a)，也隐藏了基类的virtual void f(int a), void f(double d)函数。
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Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);
Derived d;
d.f(3);
d.f(2.5);
Derived *pd = new Derived();
pd->f(3);
pd->f(2.5);同理所有用子类对象或者子类指针来调用f()函数时，都只执行virtual void f(int a)，输出virtual Derived::f(int a)
[html] view plaincopyprint Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);
Base *pBase = new Derived();
pBase->f(5);
pBase->f(3.5);pBase->f(5)，首先去Base类中寻找相应的函数，同理Base类中的两个函数virtual void f(int a)和void f(double d)是