Question

从命令行输入半径，求圆面积和球体积，用JAVA进行编程

Answer 1

package com.demo;import java.io.BufferedReader;
import java.io.InputStreamReader;import com.sun.swing.internal.plaf.metal.resources.metal;//设计一个圆的类circle，将半径初始化为r，获得圆的面积,体积
public class Circle {
double r ;
double area;
public Circle(double r){
this.r = r;
}
public double calArea(){
return Math.PI * r * r;
}
private double calVolume() {
return (4/3)*r*r*r*3.14;
}
public static void main(String args[]){
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String str = null;
double r = 0;
try{
str = br.readLine();
r = Double.parseDouble(str);
}catch(Exception e){
System.out.println("您的输入有误，请重新输入");
e.printStackTrace();
}
Circle circle = new Circle(r);
double area = circle.calArea();
double volume = circle.calVolume();
System.out.println("半径为"+r+"的圆的面积是："+area+" 半径为"+r+"的球的体积是："+volume);
}

}