关于继承/方法重写C ++的问题

Question

class Class1
{
public:
    void print()
    {
        cout << "test" << endl;
    }

    void printl()
    {
        print();
    }
};

class Class2 : public Class1
{
public:
    void print()
    {
        cout << "test2" << endl;
    }
};

Why does print() not get overridden in Class2, is there any way a function can be overridden like this? (Without virtual functions). Thanks

    Class2 t;
    t.printl();

Answer 1

No. This is the entire reason for virtual functions.

Without a virtual method here, when printl() calls print(), it's calling Class1.print() , which prints "test". If you flag the method as virtual, then it will handle it as you were expecting.

Answer 2

No, there is no way to override non-virtual functions. That's what virtual functions are for.

Answer 3

What you want is called a virtual method . Simply write virtual void print() where you currently have void print() , and it will work as you expect. Be aware that this will not work in constructors or destructors.

Answer 4

The call to print inside of printl is not overriden because it's not a virtual method. It`sa non-virtual method and hence is being invoked non-virtually. If you want to be overridable by a child class then make it virtual.

Answer 5

Imagine you had Class2, Class3 and Class3, all "overriding" Class1's "print" method.

When Class1::printl is called - how is it meant to know which of the 3 overrides to call? Without virtual methods the printl implementation has no way of knowing which overriding method to choose.