问题及代码:
【项目-动物这样叫】
下面是给出的基类Animal声明和main()函数。
class Animal
{
public:
virtual void cry()
{
cout<<"不知哪种动物,让我如何学叫?"<<endl;
}
};
int main( ){
Animal *p;
p = new Animal();
p->cry();
Mouse m1("Jerry",'m');
p=&m1;
p->cry();
Mouse m2("Jemmy",'f');
p=&m2;
p->cry();
Cat c1("Tom");
p=&c1;
p->cry();
Dog d1("Droopy");
p=&d1;
p->cry();
Giraffe g1("Gill",'m');
p=&g1;
p->cry();
return 0;
}
程序的运行结果将是:
1、根据给出的main()函数和运行结果的提示,设计出相关的各个类,注意观察运行结果,提取出每个类中需要的数据成员,并匹配上需要的成员函数。
#include <iostream>
#include <string>
using namespace std;
class Animal
{
public:
virtual void cry()
{
cout<<"不知哪种动物,让我如何学叫?"<<endl;
}
};
class Mouse :public Animal
{
public:
Mouse(string nam,char s):name(nam),sex(s){}
void cry()
{
if(sex=='m')
cout<<"我叫"<<name<<",是一只男老鼠,我的叫声是:吱吱吱!"<<endl;
else
cout<<"我叫"<<name<<",是一只女老鼠,我的叫声是:吱吱吱!"<<endl;
}
private:
string name;
char sex;
};
class Cat:public Animal
{
private:
string name;
public:
Cat(string nam):name(nam){}
void cry()
{
cout<<"我叫"<<name<<",是一只猫,我的叫声是:喵喵喵!"<<endl;
}
};
class Dog:public Animal
{
private:
string name;
public:
Dog(string nam):name(nam){}
void cry()
{
cout<<"我叫"<<name<<",是一只狗,我的叫声是:汪汪汪!"<<endl;
}
};
class Giraffe:public Animal
{
private:
string name;
char sex;
public:
Giraffe(string nam,char s):name(nam),sex(s){}
void cry()
{
if(sex=='m')
cout<<"我叫"<<name<<",是一只男长颈鹿,我的脖子太长,发不出声音来!"<<endl;
else
cout<<"我叫"<<name<<",是一只女长颈鹿,我的脖子太长,发不出声音来!"<<endl;
}
};
int main( ){
Animal *p;
p = new Animal();
p->cry();
Mouse m1("Jerry",'m');
p=&m1;
p->cry();
Mouse m2("Jemmy",'f');
p=&m2;
p->cry();
Cat c1("Tom");
p=&c1;
p->cry();
Dog d1("Droopy");
p=&d1;
p->cry();
Giraffe g1("Gill",'m');
p=&g1;
p->cry();
return 0;
}
运行结果:
知识点总结:
虚函数
学习心得: