看一段简单的程序,高分相送.急!!!!!!!!

你的void Circle(Point A,double diam)--------这不是一个构造方法,他是void型的普通方法.构造方法不应有返回值.-----也就是说
myshape[3]=new Circle(A,diam)-------不能生成一个正确的对象.
而你的myshape[3]=new Circle(A,diam);/*这具有毛病*/
用的应该是一个Circle类的构造方法.
怀疑是你的void 应该去掉.Circle(Point A,double diam).

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哈哈,不好意思,吧public打成void了,又没查出来.改后的程序变成这段,但还是不
行.这该如何是好?package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/class Point { public Point() {x=0;y=0;
 }
 public Point(double x,double y){
 this.x=x;this.y=y;
 }
 public double distance (point Z){
 double a=(this.x-Z.x)*(this.x-Z.x)+(this.y-Z.y)*(this.y-Z.y);
 return Math.sqrt(a);
 }
 public static double distance (point M,point N){
 double a=(M.x-N.x)*(M.x-N.x)+(M.y-N.y)*(M.y-N.y);
 return Math.sqrt(a);
 }
 private double x,y;
------------------------------------------------------------------
package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/class Shape {
private double length;
private double area;
}
-----------------------------------------------------
package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/public interface Shapetools {
double PI=3.14;
void getLength(Shape shape){}
void getArea(Shape shape){}
}
------------------------------------------------------
package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/
import myshapes.*;
class Circle extends Shape implements Shapetools{
Point A;
double diam;
public Circle(){
this.A=new Point(0,0);
diam=0;
}
public Circle(Point A,double diam){
this.A=new Point();
this.A.x=A.x;
this.A.y=A.y;
this.diam=diam;
}
public void getLength(){
length=PI*2*diam;
System.out.printIn("the leng of the circle is"+leng);
}
public void getArea(){
area=PI*diam*diam;
System.out.printIn("the area of the circle is"+area);
}}
-------------------------------------------------------------
package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/
import myshapes.*;
class Rect extends Shape implements Shapetools{
Point A,B;
public Rect (){
A=new Point(0,0);
B=new Point(1,1);
}
public Rect(Point A,Point B){
this.A=new Point();
this.B=new Point();
this.A.x=A.x;
this.A.y=A.y;
this.B.x=B.x;
this.B.Y=B.y;
}
public void getLength(){
double a=Math.abs(A.x-B.x);
double b=Math.abs(A.y-B.y);
length=2*(a+b);
System.out.printIn("the length of the rectangle is"+length);
}
public void getArea(){
double a=Math.abs(A.x-B.x);
double b=Math.abs(A.y-B.y);
area=a*b;
System.out.printIn("the area of the rectangle is"+area);
}
}
---------------------------------------------------------------
package myshapes;/**
* Title: 
* Description: 
* Copyright: Copyright (c) 2002
* Company: 
* @author unascribed
* @version 1.0
*/
import myshapes.*;
class Myshapes {
private static Point A=new Point();
private static Point B=new Point(2,2);
public static void main(String Args[]){
InputStreamReader ir;
BufferedReader in;
ir=new InputStreamReader(System.in);
in=new BufferedReader(ir);
System.out.printIn("please input the diam:");
String s=In.readLine();
double diam=Integer.parseInt(s);
Shape myshape[]=new Shape[4];
myshape[0]=new Rect();
myshape[1]=new Rect(A,B);
myshape[2]=new Circle();
myshape[3]=new Circle(A,diam);//这句有毛病
for(int i=0;i<4;i++)myshape[i].getLength;//这句有毛病
for(int i=0;i<4;i++)myshape[i].getArea;
}
}
_______________________________________________________________
哦，你应该把myshape数组定义大一些，至少应该是5个，因为数组的最后一个是存储终止符的。Shape myshape[]=new Shape[4];应为Shape myshape[]=new Shape[5];
你试一下？
还是不行啊.
信息是:
     not an expression statement in line __(即第一句)
     not an expression statement in line __(即第二句)
1 public interface Shapetools {
 public static final double PI=3.14;
 void getLength();
 void getArea();
 }
myshape[3]=new Circle(A,diam);//这句有毛病
for(int i=0;i<4;i++)
 myshape[i].getLength();//这句有毛病
for(int i=0;i<4;i++)
 myshape[i].getArea();
getLength()和getArea()是方法，调用时应该带上()：
for(int i=0;i<4;i++)myshape[i].getLength();
for(int i=0;i<4;i++)myshape[i].getArea();