Java题 编写一个shape接口，该接口包含一个常量PI表示圆周率;两个方法:一个求周长和一个求面积
1.接口定义如下：
public interface Shape {
public final double Pi=3.141596;
public double area(double r);
public double length(double r);
}
2.测试类如下：
public class Circle implements Shape {
@Override
public double area(double r) {
// TODO Auto-generated method stub
return r*r*Pi;
}
@Override
public double length(double r) {
// TODO Auto-generated method stub
return 2*r*Pi;
}
public static void main(String[] args){
Circle c= new Circle();
double r=1.234;
System.out.println("\nThis is area: "+c.area(r));
System.out.println("\nThis is length: "+c.length(r));
}
}
//测试类答案如下;
This is area: 4.783884158576
This is length: 7.753458928
public interface Shape {
public final double Pi=3.141596;
public double area(double r);
public double length(double r);
}
2.测试类如下：
public class Circle implements Shape {
@Override
public double area(double r) {
// TODO Auto-generated method stub
return r*r*Pi;
}
@Override
public double length(double r) {
// TODO Auto-generated method stub
return 2*r*Pi;
}
public static void main(String[] args){
Circle c= new Circle();
double r=1.234;
System.out.println("\nThis is area: "+c.area(r));
System.out.println("\nThis is length: "+c.length(r));
}
}
//测试类答案如下;
This is area: 4.783884158576
This is length: 7.753458928
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第1个回答 2014-12-04
public interface Shape {
// 圆周率
double PI = 3.14;
/**
* @param radius
* 半径
* @return 面积
*/
public double area(double radius);
/**
*
* @param radius
* 半径
* @return 周长
*/
public double girth(double radius);
}
//下面是实现类
public class ShapeImpl implements Shape {
@Override
public double area(double radius) {
return radius * radius * PI;
}
@Override
public double girth(double radius) {
return radius * 2 * PI;
}
}
// 圆周率
double PI = 3.14;
/**
* @param radius
* 半径
* @return 面积
*/
public double area(double radius);
/**
*
* @param radius
* 半径
* @return 周长
*/
public double girth(double radius);
}
//下面是实现类
public class ShapeImpl implements Shape {
@Override
public double area(double radius) {
return radius * radius * PI;
}
@Override
public double girth(double radius) {
return radius * 2 * PI;
}
}
第2个回答 2014-12-04
public interface Shape{
double PI = 3.14;
double area(double r);
double zhouchang(double r);
}
public class ShapeImpl implement Shape{
private r;
ShapeImpl(double r){
this.r = r;
}
@override
public double area(double r){
return r*r* Shape.PI;
}
@override
public double zhoucahng(double r){
reuturn r*2*PI;
}
}
double PI = 3.14;
double area(double r);
double zhouchang(double r);
}
public class ShapeImpl implement Shape{
private r;
ShapeImpl(double r){
this.r = r;
}
@override
public double area(double r){
return r*r* Shape.PI;
}
@override
public double zhoucahng(double r){
reuturn r*2*PI;
}
}
第3个回答 2014-12-04
对
