定义一个圆类,数据成员半径,函数成员周长和面积,定义构造函数

classDate{public:Date(int=1900,int=1,int=1);voidShowDate();Dateoperator++();//前置单目运算符重载Dateoperator+

#include#includeusingstd::cout;usingstd::cin;usingstd::endl;usingstd::string;classBook{public:Book(s

//ConsoleApplication4.cpp:定义控制台应用程序的入口点.//#include"stdafx.h"#includeusingnamespacestd;classcMyRect{p

classCircle{public:Circle(intnr){r=nr;}Circle(){}public:intr;intArea(){return3.14*r*r;}};classB{publ

#includeusingnamespacestd;classcircle{private:doubleradius;public:circle(doubler=0.0);voidinput();do

classTriangle{private:\x05doublea;\x05doubleb;\x05doublec;public:\x05Triangle():a(0),b(0),c(0){}\x05

#include#definePI3.14159classCircle{private:floatradius,girth,area;public:Circle(floatr=0);//构造函数（以半

classComplex{public:Complex(){real=0;imag=0;}//定义结构函数Complex(doubler,doublei){real=r;imag=i;}//构造函数重

classcircle{floatradius;floatarea;public:circle(floatr){radius=r;}floatgetarea(void){area=3.14*radiu

把这三个类分别放到三个.java文件中,然后编译运行即可.publicclassCircle{privatedoubler;publicCircle(doubler){this.r=r;}public

classcircle{public:circle(){radius=0;}circle(doubleradiuv){radius=radiuv;}voidgetparimeter(){parimet

classCat{privateintnumofcats;publicintgetnumofcats(){returnnumofcats;}}

#includeusingnamespacestd;classCircle{public:Circle(doubler=0):radius(r){}doubleArea(){return3.14*ra

在此基础上派生出矩形类CRectangle和圆类CCircle.//矩形类包括左上角坐标、长和宽等数据成员及相关的成员函数（如计算面积、周长、显示矩形的属性值等）.//圆类包括圆心坐标、半径等数据成员

#include#includeusingnamespacestd;classCircle{public:\x05Circle(){}\x05Circle(Circle&c)\x05{\x05\x05

classCircle{intr,c,s;c=circle(r);s=square(r);}intcircle(intr){intc;c=2*3.1415926*r;return(c);}intsqu

这个是pascal的做法programabcconstpai=3.14varR,Area:real;beginwriteln("pleaseinputanumberforr:");readln(r);

#includeclasscircle{private:intr;public:voidinput(){cout

#include#definePI3.14159usingnamespacestd;classcircle{private:doubleRadius;public:voidjiandan();};vo

1)Youdon'tneedamemberfunction2)Youdon'tevenneedamembervariable3)Aclasscanbeempty再问：ok，Iunderstand，th