java類circle

『壹』 java 定義一個圓類Circle

public class Circle {
double radius;

public Circle(double rad) {
radius = rad;
}
public double calcArea() {
return Math.PI * radius * radius;
}
public static void main(String[] args) {
Circle c = new Circle(3);
System.out.println(c.calcArea());
}
}

『貳』 java 定義一個圓類Circle，就解

publicclassCircle{
//圓的半徑
privatedoubleradius;

//求圓的面積
publicdoublefindArea(){
returnMath.PI*radius*radius;
}

publicdoublegetRadius(){
returnradius;
}

publicvoidsetRadius(doubleradius){
this.radius=radius;
}
}

測試類自己去寫。

『叄』 JAVA中怎麼定義一個圓類 要求如下

public class Circle {
private double r;

public Circle(double r) {
this.r = r;
}

public double getR() {
return r;
}

public void setR(double r) {
this.r = r;
}

/**
* 面積
*
* @return
*/
public double getArea() {
return Math.PI * Math.pow(r, 2);
}

/**
* 周長
*
* @return
*/
public double getLong() {
return Math.PI * r * 2;
}
}class Cylinder extends Circle {
private double h;

public Cylinder(double r, double h) {
super(r);
this.h = h;
}

public double getH() {
return h;
}

public void setH(double h) {
this.h = h;
}

/**
* 體積 = 底面積*高
*
* @return
*/
public double getVolume() {
return super.getArea() * h;
}

/***
* 表面積=測面積+2個底面積
*
* @return
*/
public double getSurfacearea() {
return super.getLong() * h + 2 * super.getArea();
}

}
測試代碼就不寫了

『肆』 java類的創建，Circle

package test;

public class Circle {

private double radius;
private double area;
private double diameter;

public double calDiameter(){
return 2 * radius;
}

public double calArea(){
return Math.PI * calDiameter();
}

public double getRadius() {
return radius;
}
public void setRadius(double radius) {
this.radius = radius;
}
public double getArea() {
return area;
}
public void setArea(double area) {
this.area = area;
}
public double getDiameter() {
return diameter;
}
public void setDiameter(double diameter) {
this.diameter = diameter;
}

}

public class Pizza{
private String type;
private double size;
private double price;
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public double getSize() {
return size;
}
public void setSize(double size) {
this.size = size;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}

『伍』 急求Java代碼，定義一個Circle(圓類型）

public class Exam
{
public static void main(String[] args)
{
Circle c=new Circle(3,4,5);
System.out.printf("圓心：(%f,%f)，半徑：%f，面積：%f",c.x,c.y,c.r,c.countArea());
}
}

class Circle
{
public Circle()
{
this(0,0,0);
}
public Circle(double x,double y,double r)
{
this.x=x;
this.y=y;
this.r=r;
}
public double countArea()
{
return Math.PI*r*r;
}
/*private*/public double x,y,r;
}

『陸』 java設計一個Circle（圓）類，計算圓的面積和周長，並輸出圓的半徑、面積和周長

第一個圓類計算第一個圓類計算圓的面積和周長並輸出圓的半徑，面積和周長這個圓的面積當然是有公式來計算的

『柒』 用JAVA寫一個名circle的類表示一類同心圓

classcircle{
privatedoubleradius=0;
privateintx=0;
privateinty=0;
publiccircle(intx,inty,doubleradius){
this.x=x;
this.y=y;
this.radius=radius;
}
publiccircle(circleothercircle,doubleradius){
this.x=othercircle.getX();
this.y=othercircle.getY();
this.radius=radius;
}
publicgetRadius(){
returnthis.radius;
}
publicgetX(){
returnthis.x;
}
publicgetY(){
returnthis.y;
}
publicgetArea(){
returnmath.pi*this.radius*this.radius;
}
}

『捌』 java編程:定義一個圓circle類,包含如下內容

代碼如下：

importjava.util.Scanner;

classCircle{
	
	privatedoubleradius;

	publicCircle(doubleradius){
		this.radius=radius;
	}

	publicdoublegetRadius(){
		returnradius;
	}

	publicvoidsetRadius(doubleradius){
		this.radius=radius;
	}
	
	publicdoublegetArea(){
		returnMath.PI*radius*radius;
	}
	
	publicdoublegetPerimeter(){
		return2*Math.PI*radius;
	}
}

publicclassApp{
	
	publicstaticvoidmain(String[]argv){
		
		Scannerscanner=newScanner(System.in);
		
		System.out.print("請輸入圓半徑：");
		
		doubler=scanner.nextDouble();
		
		
		Circlec=newCircle(r);
		
		System.out.println("面積："+c.getArea()+"，周長："+c.getPerimeter());
	}
}

運行結果：

『玖』 JAVA基礎實現圓類Circle

/////寫著也夠累的....

public class Cylinder extends Circle{

private double h;

public Cylinder(double h, double r, int x, int y) {
super(r, x, y);
this.h = h;
}

public Cylinder(){

}

public double getH() {
return h;
}

public void setH(double h) {
this.h = h;
}

public double area(){
return 2 * super.area() + super.perimeter() * h;
}

public double volume() {
return super.area() * h;
}

public static void main(String[] args) {
Cylinder cy = new Cylinder(4.5, 2.3, 2 , 3);
System.out.println("area: " + cy.area());
System.out.println("volume: " + cy.volume());
}

}
class Circle{
private int x;
private int y;
private double r;

public Circle(){

}

public Circle(double r, int x, int y) {
this.r = r;
this.x = x;
this.y = y;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public double getR() {
return r;
}
public void setR(double r) {
this.r = r;
}

public double perimeter(){
return 2 * Math.PI * r;
}

public double area(){
return Math.PI * r * r;
}

}

『拾』 JAVA：定義一個圓類Circle，成員變數：半徑 radius

#include <iostream.h>

class Circle
{
public:
Circle():m_radius(5){}
Circle(int radius):m_radius(radius){}

int getRadius(){return m_radius;}
void Setradius(int radius){if(radius<1) radius=1; m_radius=radius;}

int compareCircle(Circle &h)
{
return m_radius-h.m_radius;
}

private:
int m_radius;
};

int main(void)
{
Circle a;
Circle b(8);
int result=a.compareCircle(b);
if(result>0)
cout<<"Circle a is larger than Circle b."<<endl;
else if(result<0)
cout<<"Circle a is smaller than Circle b."<<endl;
else
cout<<"Circle a is equal to Circle b."<<endl;
cout<<"Press any ket to continue..."<<endl;
cin.get();
return 0;
}