constructor01.cpp

数据结构常用算法合集

//constructor01.cpp
#include <iostream.h>
#include <conio.h>
const float PI = 3.14159;
class  Area
{ private:
  int  radius;
  float  area;
 public:
    Area();							//无参构造函数
    Area(int);						//1个参数的构造函数
    Area(int,float);					//两个参数的构造函数
    inline float list_area();				//inline的原型
 };
 Area::Area()						//构造函数定义
 { radius=0;							//清除数据
   area=0;
   cout <<"我是无数构造函数\n";
 }
 Area::Area(int _radius)
 { radius = _radius;
   area = PI * radius * radius;
   cout <<"我是1个参数的构造函数\n";
 }
 Area::Area(int _radius,float _area)
 { radius = _radius;					//设置某一数据
   area = _area;
   cout <<"我是两个参数的构造函数\n";
 }
 inline float Area::list_area()			//inline函数
 { return  area;}
 void main()
 { Area circle;	 					//对象声明 circle
   cout << "面积="<< circle.list_area();		//输出数据
   cout << endl;
   int _radius = 10;
   Area circle_1(_radius);
   cout << "面积="<< circle_1.list_area();	//输出数据
   cout << endl;
   float _area=PI*_radius*_radius;
   Area circle_2(_radius,_area);  			//对象声明 circle_2
   cout << "面积="<< circle_2.list_area();	//输出数据
   getch();
 }