矩形的周长面积
- 定义一个矩形类Rec,包含私有属性length、width,包含公有成员方法:
- 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,将长度的值返回给调用处
- int get_width(); //获取宽度,将宽度的值返回给调用处
- void show(); //输出周长和面积
代码
#include <iostream>using namespace std;class Rec
{const int length;int width;
public:void set_length(int l);void set_width(int w);int get_length();int get_width();void show();Rec():length(3),width(4){cout<<"无参:"<<endl;cout <<"C:"<<2*(length+width)<<endl;cout <<"S:"<<length*width<<endl;}Rec(int width):length(5){cout <<"有参"<<endl;cout <<"C:"<<2*(length+width)<<endl;cout <<"S:"<<length*width<<endl;}
};void Rec::set_width(int width)
{this->width=width;
}
int Rec::get_length()
{return length;
}int Rec::get_width()
{return width;
}void Rec::show()
{cout <<"C:"<<2*(length+width)<<endl;cout <<"S:"<<length*width<<endl;}
int main()
{Rec r1;Rec r2(4);r2.set_width(6);r2.show();return 0;
}
实现效果
圆的参数
- 定义一个圆类,包含私有属性半径r,公有成员方法:
- void set_r(int r); //获取半径
- void show //输出周长和面积,show函数中需要一个提供圆周率的参数PI,该参数有默认值3.14
代码
#include <iostream>using namespace std;class yuan
{int &r;
public:void set_r(int r);void show();yuan(int &r):r(r){cout <<"C="<<2*3.14*(float)r<<endl;cout <<"S="<<3.14*(float)r*(float)r<<endl;}
};void yuan::set_r(int r)
{this->r=r;
}void yuan::show()
{cout <<"C="<<2*3.14*(float)r<<endl;cout <<"S="<<3.14*(float)r*(float)r<<endl;
}int main()
{int R=7;yuan r1(R);return 0;
}
实现效果
汽车的品类
- 定义一个Car类,包含私有属性,颜色color,品牌brand,速度speed,包含公有成员方法:
- void display(); //显示汽车的品牌,颜色和速度
- void acc(int a); //加速汽车
- set函数,设置类中的私有属性
代码
#include <iostream>
#include <iomanip>using namespace std;class Car
{string cloor;string ip;int speed;
public:void display();void acc(int a);void set_look(string c,string i,int s);Car():cloor("black"),ip("别克"),speed(350){cout <<"无参的构造函数:"<<endl;cout <<"颜色:"<<setw(8)<<left<<cloor<<"品牌:"<<setw(8)<<left<<ip<<"速度:"<<setw(8)<<left<<speed<<endl;}Car(string cloor,string ip,int speed){this->cloor=cloor;this->ip=ip;this->speed=speed;cout <<"有参的构造函数"<<endl;cout <<"颜色:"<<setw(8)<<left<<cloor<<"品牌:"<<setw(8)<<left<<ip<<"速度:"<<setw(8)<<left<<speed<<endl;}
};void Car::display()
{cout <<"颜色:"<<setw(8)<<left<<cloor<<"品牌:"<<setw(8)<<left<<ip<<"速度:"<<setw(8)<<left<<speed<<endl;
}
void Car::acc(int a)
{speed+=a;
}
void Car::set_look(string cloor,string ip,int speed)
{this->cloor = cloor;this->ip = ip;this->speed=speed;
}int main()
{Car bieke;Car penz("white","BWM",400);penz.set_look("red","benz",360);penz.acc(100);penz.display();return 0;
}
实现效果
知识点思维导图