#include <iostream>
using namespace std;
class Rec
{int length;int width;
public:void set_length(int l);  //设置长度void set_width(int w); //设置宽度int get_length();      //获取长度int get_width();       //获取宽度void show();           //输出周长和面积
};
void Rec::set_length(int l)
{length=l;
}
void Rec::set_width(int w)
{width=w;
}
int Rec::get_length()
{return length;
}
int Rec::get_width()
{return width;
}
void Rec::show()
{cout << "周长=" << get_length()+get_width() <<endl;cout << "面积=" << get_length()*get_width() <<endl;
}
int main()
{Rec p;p.set_length(6);p.set_width(5);p.show();return 0;
}

 

#include <iostream>
using namespace std;
class Yuan
{   double PI=3.14;int r;
public:void set_r(int sum);  //设置半径void show();           //输出周长和面积
};
void Yuan::set_r(int sum)
{r=sum;
}
void Yuan::show()
{cout << "周长=" << 2*PI*r << endl;cout << "面积=" << PI*r*r <<endl;
}
int main()
{Yuan p;p.set_r(5);p.show();return 0;
}

 

 

#include <iostream>
using namespace std;
class Car
{string brand;string color;int speed;
public:void display();void accelerate(int amount);void set (string b,string c,int s);
};
void Car::display()
{cout << "品牌：" << brand <<endl;cout << "颜色：" << color <<endl;cout << "速度：" << speed <<endl;
}
void Car::accelerate(int amount)
{speed=speed+amount;
}
void Car::set(string b, string c, int s)
{brand=b;color=c;speed=s;
}
int main()
{Car p;p.set("Volvo","black",100);p.display();p.accelerate(20);p.display();return 0;
}