矩形类 求面积

 1 package org.hanqi.pn0120;
 2 
 3 public class juxing {
 4     
 5     juxing()
 6     {
 7         chang=10;
 8         kuan=9;
 9     }
10     //属性
11     double chang;
12     
13     double kuan;
14     
15     //行为
16     void mianji()
17     {
18         System.out.println("矩形面积="+chang*kuan);
19     }
20     
21     public static void main(String[] args) {
22     
23         juxing myjuxing=new juxing();
24         
25         myjuxing.mianji();
26         
27         myjuxing.chang=16;
28         
29         myjuxing.kuan=6;
30         
31         myjuxing.mianji();
32         
33 
34 
35     }
36 }