创建类

 1 package duix;
 2 
 3 public class Shu {
 4 
 5     //书的种类
 6     public String Shuzl;
 7     
 8     //书的名字
 9     public String Shumz;
10     
11     //某本书的限定额
12     int Shuxde;
13     
14     //当前本书的数量
15     int Dangqsl;
16     
17     public Shu(String shuzl,String shumz,int shuxde)
18     {
19         this.Shuzl = shuzl;
20         this.Shumz = shumz;
21         this.Shuxde = shuxde;
22     }
23     
24     //增添书本
25     public void Zengjia(int Zengsl)
26     {
27         //实际增添书本的数量
28         int sjzsl = Shuxde - Dangqsl;
29         
30         Dangqsl += Zengsl;
31         
32         //本书已达限定额
33         if (Dangqsl >= Shuxde)
34         {
35             System.out.println("本书已达限定额，请停止增添");
36             
37             Dangqsl = Shuxde;
38             
39         }
40         else
41         {
42             sjzsl = Zengsl;
43         }
44 
45         System.out.println("增添书量 =" + Zengsl + ",当前本书数量 =" + Dangqsl);
46     }
47     //每本书单价
48     public int Danjia = 50; 
49     
50     //出售书本
51     public void Chushou(int Shengyusl)
52     {
53         int Shouchusl = Shuxde - Shengyusl;
54         
55         Dangqsl -= Shouchusl;
56         
57         System.out.println("剩余书本数量 =" + Shengyusl + "当前书本数量 =" + Dangqsl);
58         
59         int xiaoshouzj = Danjia * Shengyusl;
60         
61         System.out.println("销售总价 =" + xiaoshouzj);
62     }
63     
64     
65 }
66 
67 
68 
69 
70 
71 
72 
73 package duix;
74 
75 public class shutest {
76 
77     public static void main(String[] args){
78         
79         Shu shu = new Shu("小说","红楼梦",40);
80         
81         shu.Dangqsl = 10;
82         
83         shu.Zengjia(20);
84         
85         shu.Danjia= 50;
86         
87         shu.Chushou(20);
88         
89         
90         //书
91         Shu shu1 = new Shu("","",30);
92         
93         shu1.Danjia = 50;
94