Java定义一个圆类,半径r,求周长2πpiπr 求面积piπrπr

就是类里面定义的一个字符串,数值,list,map等这样的一个变量或者常量/***这是Manager类*/publicclassManager{Stringusername="张三";//定义Mana

classscore{privatedoubleenglish;publicvoidsetScore(doubleenglish){this.english=english;}publicvoidpr

importjava.util.Scanner;classRound{\x09publicdoubleperimeter(doubleradius){\x09\x09returnradius*2;\x

classCircle{\x09privatedoubler;\x09publicvoidsetR(doubler)\x09{\x09\x09this.r=r;\x09}\x09publicdoubl

classTriangle{inta,b,c,l;publicstaticvoidperimeter(){l=a+b+c;}}publicclassTriangleTest{publicstaticv

楼上的方法应该没错,可感觉对于表现java面向对象的特性没有表现出来,下面是我写的,应该非常清楚明了了importjava.io.BufferedReader;importjava.io.InputS

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

引入包类我还没有学,不好意思.希望对你有助.classCicle//定义圆类.{doublearea(doubler)//定义方法计算圆的面积.{return3.14*r*r;}}classTest5

类似的问题,在知道里面不知道有多少.搜索一下.

publicclassTest{\x05publicstaticvoidmain(String[]args){\x05\x05Rectangler=newRectangle(5,4);\x05\x05

packagecom.test;publicclassComplexNum{\x05//Z=a+bi\x05privateintRez;\x05//实部\x05privateintImz;\x05//

classcircle{public:circle(floatr=0){this->r=r;}floatarea();{return3.14*r*r;}private:floatr;};再问：再问：为

publicclassPoint{privatedoublex;privatedoubley;publicPoint(doublex,doubley){this.x=x;this.y=y;}publi

public class Ring{    private double inner;//内半径  

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

classClock{privateinthourse;privateintminute;privateintsecond;publicClock(){this.hourse=0;this.minut

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

publicclassTriangle{\x09inta;\x09intb;\x09intc;\x09publicTriangle(inta,intb,intc){\x09\x09this.a=a;\

publicclassCircle{privatedoubleradius;publicCircle(doubler){this.radius=r;}publicstaticvoidmain(Stri

publicclassCircle{\x09privatedoubler;//圆的半径\x09\x09publicCircle(doubler){\x09\x09this.r=r;\x09}\x09\