C++快速入门---覆盖方法和重载方法(13)
覆盖方法(overriding)
覆盖:在基类里提供一个通用函数,但在它的某个子类里需要修改这个方法的实现。
子类覆盖基类的方法。
修改例题,为我们的Animal添加eat()方法,并在Pig和Turtle中覆盖。
#include <iostream>
#include <string>
class Animal//基本
{
public:
Animal(std::string theName);
void eat();
void sleep();
void drool();//流口水
protected:
std::string name;
};
//Pig继承于Animal
class Pig : public Animal
{
public:
Pig(std::string theName);
void climb();//上树
void eat();//new!
};
class Turtle : public Animal
{
public:
Turtle(std::string theName);
void swim();
void eat(); //new!
};
Animal::Animal(std::string theName)
{
name = theName;
}
void Animal::eat()
{
std::cout << "I'm eatting!" << std::endl;
}
void Animal::sleep()
{
std::cout << "I'm sleeping!Don't disturb me!" << std::endl;
}
void Animal::drool()
{
std::cout << "我是公的,看到母的我会流口水,我正在流口水。。。" << std::endl;
}
Pig::Pig(std::string theName) : Animal(theName)
{
}
void Pig::climb()
{
std::cout << "我是一只漂亮的小母猪猪,我会上树,我正在爬树。。嘘。。" << std::endl;
}
void Pig::eat()
{
Animal::eat();
std::cout << name << "正在吃鱼!\n\n"; //new!
}
Turtle::Turtle(std::string theName) : Animal(theName)
{
}
void Turtle::swim()
{
std::cout << "我是一只小甲鱼,当母猪想抓我的时候,我就游到海里。。哈哈。。" << std::endl;
}
void Turtle::eat()
{
Animal::eat();
std::cout << name << "正在吃东坡肉!\n\n"; //new!
}
int main()
{
Pig pig("小猪猪");
Turtle turtle("小甲鱼");
//std::cout << "这只猪的名字是:" << pig.name << std::endl; //错误
///std::cout << "每只乌龟都有个伟大的名字:" << turtle.name << std::endl; //错误
pig.eat();
turtle.eat();
pig.climb();
turtle.swim();
return 0;
}
重载方法
重载机制使你可以定义多个同名的方法(函数),只是它们的输入参数必须不同。(因为编译器是依靠不同的输入参数来区分不同的方法)
对eat()方法进行重载:test
#include <iostream>
#include <string>
class Animal//基本
{
public:
Animal(std::string theName);
void eat();
void eat(int eatCount);
void sleep();
void drool();//流口水
protected:
std::string name;
};
//Pig继承于Animal
class Pig : public Animal
{
public:
Pig(std::string theName);
void climb();//上树
};
class Turtle : public Animal
{
public:
Turtle(std::string theName);
void swim();
};
Animal::Animal(std::string theName)
{
name = theName;
}
void Animal::eat()
{
std::cout << "I'm eatting!" << std::endl;
}
void Animal::eat(int eatCount)
{
std::cout << "我吃了" << eatCount << "碗馄饨!\n\n";
}
void Animal::sleep()
{
std::cout << "I'm sleeping!Don't disturb me!" << std::endl;
}
void Animal::drool()
{
std::cout << "我是公的,看到母的我会流口水,我正在流口水。。。" << std::endl;
}
Pig::Pig(std::string theName) : Animal(theName)
{
}
void Pig::climb()
{
std::cout << "我是一只漂亮的小母猪猪,我会上树,我正在爬树。。嘘。。" << std::endl;
}
Turtle::Turtle(std::string theName) : Animal(theName)
{
}
void Turtle::swim()
{
std::cout << "我是一只小甲鱼,当母猪想抓我的时候,我就游到海里。。哈哈。。" << std::endl;
}
int main()
{
Pig pig("小猪猪");
Turtle turtle("小甲鱼");
pig.eat();
turtle.eat();
pig.eat(15);
pig.climb();
turtle.swim();
return 0;
}