土豆土豆你才是马铃薯

摘要： package demo1package; public class Cylinder { private double radius; private double pi; public void setnumber(double r,double p){//公共方法用于对私有成员进行访问 if( 阅读全文

摘要： void area()方法与 double area()方法、传入参数方法的区别 package demo1package; public class Cylinder { double r; double pi; /*public class Cylinder { double r; double 阅读全文