实验4 继承
作者：互联网
- 实验任务二
source code ：
1 #include <iostream>
2 #include <typeinfo>
3
4 // definitation of Graph
5 class Graph
6 {
7 public:
8 void draw() { std::cout << "Graph::draw() : just as an interface\n"; }
9 };
10
11
12 // definition of Rectangle, derived from Graph
13 class Rectangle : public Graph
14 {
15 public:
16 void draw() { std::cout << "Rectangle::draw(): programs of draw a rectangle\n"; }
17 };
18
19
20 // definition of Circle, derived from Graph
21 class Circle : public Graph
22 {
23 public:
24 void draw() { std::cout << "Circle::draw(): programs of draw a circle\n"; }
25 };
26
27
28 // definitaion of fun(): as a call interface
29 void fun(Graph *ptr)
30 {
31 std::cout << "pointer type: " << typeid(ptr).name() << "\n";
32 std::cout << "RTTI type: " << typeid(*ptr).name() << "\n";
33 ptr -> draw();
34 }
35
36 // test
37 int main()
38 {
39 Graph g1;
40 Rectangle r1;
41 Circle c1;
42
43 // call by object name
44 g1.draw();
45 r1.draw();
46 c1.draw();
47
48 std::cout << "\n";
49
50 // call by object name, and using the scope resolution operator::
51 r1.Graph::draw();
52 c1.Graph::draw();
53
54 std::cout << "\n";
55
56 // call by pointer to Base class
57 fun(&g1);
58 fun(&r1);
59 fun(&c1);
60 }
The Running results ：
对代码稍作改动，在基类Graph的成员函数draw()前面加一个关键字virtual，重新编译运行程序，再次观察结果，对比一下
如果派生类中声明了与基类成员函数同名的新函数,即使函数的参数表不同,从基类继承的同名函数的所有重载形式也都会被隐藏。
- 实验任务三
source code ：
1 #include"battery.hpp"
2 #include"car.hpp"
3 #include<iomanip>
4
5 class ElectricCar:public Car{
6 public:
7 ElectricCar(string s1,string s2,int a,int b=0,int ca=70):Car(s1,s2,a,b),battery(ca){};
8 void info() const {
9 Car::info();
10 cout<<left<<setw(20)<<"capacity: "<<battery.get_capacity()<<"-kWh"<<endl;
11 }
12 private:
13 Battery battery;
14 };
1 #include<iostream>
2 #include<string>
3
4 using namespace std;
5
6 class Battery{
7 public:
8 Battery(int b=70):capacity(b){}; //Battery
9 int get_capacity() const{return capacity;}
10 private:
11 int capacity;
12 };
1 #include<iostream>
2 #include<string>
3
4 #include<iomanip>
5
6 using namespace std;
7
8 class Car{
9
10 public:
11 Car(string s1,string s2,int a,int b=0):maker(s1),model(s2),year(a),odometers(b){};
12 void info() const {
13 cout<<left<<setw(20)<<"maker: "<<maker<<endl;
14 cout<<left<<setw(20)<<"model: "<<model<<endl;
15 cout<<left<<setw(20)<<"year: "<<year<<endl;
16 cout<<left<<setw(20)<<"odometers: "<<odometers<<endl;
17 }
18 void update_odometers(int meters){
19 if(meters<odometers){
20 cout<<"incorrect number! "<<endl;
21 }
22
23 else{
24 odometers=meters;
25 }
26
27 }
28 private:
29 string maker;
30 string model;
31 int year, odometers;
32 };
The Running results ：
- 实验任务4
source code ：
1 #include <iostream>
2 using namespace std;
3
4 class MachinePets{
5 public:
6 MachinePets(const string s):nickname(s){
7 };
8 string get_nickname() const{return nickname;};
9 virtual string talk(){
10 };
11 ~MachinePets(){
12 };
13
14 private:
15 string nickname;
16 };
17 class PetCats:public MachinePets{
18 public:
19 PetCats(const string s):MachinePets(s){
20
21 };
22
23 string talk(){
24 return "miao wu~";
25 }
26 };
27 class PetDogs:public MachinePets{
28 public:
29
30 PetDogs(const string s):MachinePets(s){
31
32 };
33 string talk(){
34 return "wang wang~";
35 }
36 };
The Running results ：
标签：const,string,继承,int,实验,MachinePets,include,public 来源： https://www.cnblogs.com/zmqh/p/15628972.html