void g(float x){ cout << "Base::g(float) " << x << endl; } void h(float x){ cout << "Base::h(float) " << x << endl; } }; class Derived : public Base { public: virtual void f(float x){ cout << "Derived::f(float) " << x << endl; } void g(int x){ cout...
virtual是虚拟的意思，表示虚函数。父类的函数会被子类继承，假如这个函数不符合子类的要求，需要重写，必须使父类的这个函数为虚函数；否则会有重复定义的错误
public: virtual void f(float x){ cout << "Derived::f(float) " << x << endl; } void g(int x){ cout << "Derived::g(int) " << x << endl; } void h(float x){ cout << "Derived::h(float) " << x << endl; } }; void main(void) { Derived d; Base *pb = &d; ...
virtual void func2(int i){ cout << "Base::func2(int i)" << endl;} 12 13 }; 14 15 16 17 class Derived : public Base 18 19 { 20 21 public: 22 23 void func(){ cout <<"Derived::func()"<< endl; } 24 25 void func2(){ cout <<"Derived::func2()"<< endl; } 26 27...
{public: Point2d(int x = , int y = ): _x(x), _y(y) {}voidprint()const{ printf("Point2d(%d, %d)\n", _x, _y); }protected:int _x;int _y;};classPoint3d :public Point2d {public: Point3d(int x = , int y = , int z = ):Point2d(x, y), _z(z) {}voidprint...
virtual void f()这是说f是一个虚函数，要在扩展类中定义后才能使用
C++中virtual的三种用法,virtual用法一usingnamespacestd;classA{public:virtualvoiddisplay(){cout<<"A"<<ENDL;}};classB:publicA{public:voiddis...
virtual void z(int z) { printf("Point2d set z: %d\n", z); } protected: int _x; int _y; }; class Point3d : public Point2d { public: Point3d(int x = 0, int y = 0, int z = 0):Point2d(x, y), _z(z) {}
A) virtual int vf(int) B) void vf(int)=0C) virtual void vf()=0 D) virtual void vf(int) 3以下( )成员函数表示纯虚函数。 A.virtual int vf(int)B.void vf(int)=0C.virtual void vf()=0D.virtual void vf(int) 4以下哪个基类中的成员函数表示纯虚函数( )。 A.virtual void vf (...
voidfunc(Animal *xyz){ xyz->eat(); }voidfunc(Cat *xyz){ xyz->eat(); } 现在func() 函数能够根据输入参数类型的不同,输出不同的内容了。可是问题来了,Animal(动物)是一个基类,它能派生出的动物远远不止Cat(猫)一种,若是派生出许多派生类,每个派生类都重载一遍 func...