Linkage of function rewriting and virtual functions: a powerful combination of dynamic binding in inheritance

Function rewriting and virtual functions work together to achieve dynamic binding in inheritance. When a derived class overrides a virtual function of the parent class, the overridden function is called at runtime based on the actual type of the object, even if the parent class does not know the existence of the derived class at compile time.

Linkage between function rewriting and virtual functions: a powerful combination of dynamic binding in inheritance

In object-oriented programming (OOP) ), function overriding and virtual functions are two closely related concepts that work together to achieve dynamic binding in inheritance. Dynamic binding allows a reference of a parent class to point to an object of its derived class and call overridden methods in the derived class, even if the parent class does not know the existence of the derived class at compile time.

Function rewriting

Function rewriting refers to defining a function in a derived class with the same name and parameters as the parent class. When a derived class object is called, the overridden method in the derived class will be called, not the method in the parent class. This allows derived classes to modify or extend behavior in the parent class.

Virtual function

A virtual function is a function declared as virtual in the parent class. When a derived class overrides a virtual function, it creates a function with the same name and parameters as the function in the parent class. This tells the compiler to call the correct function at runtime based on the object's actual type.

Practical Case

Consider the following example:

#include <iostream>

using namespace std;

class Animal {
public:
  virtual void speak() { cout << "Animal speaking" << endl; }
};

class Dog : public Animal {
public:
  void speak() override { cout << "Dog barking" << endl; }
};

int main() {
  Animal* animal = new Dog();  // 创建 Dog 对象，但使用 Animal 指针
  animal->speak();  // 调用 Dog 类的 speak() 方法
  return 0;
}

In this example:

• ##Animal is the parent class, which defines a virtual function named speak.
• Dog is a derived class that overrides the speak method to achieve different behavior.
In the
• main function, create a Animal pointer pointing to the Dog object.
When calling the
• speak method on an Animal pointer, the compiler will call the overridden based on the actual Dog object pointed to. Dog::speak method.

Output:

Dog barking

This mechanism allows us to dynamically call overridden functions based on the actual object type, thus achieving a flexible and extensible inheritance system.

The above is the detailed content of Linkage of function rewriting and virtual functions: a powerful combination of dynamic binding in inheritance. For more information, please follow other related articles on the PHP Chinese website!