设计模式——原型模式

一、任务

使用单例模式完成单一学号问题

二、类图

三、代码

1、Java

 1 package tutorial7;
 2 
 3 public class Client {
 4     public static void main(String a[])
 5     {
 6         IdnumberStudent no1,no2;
 7        no1=IdnumberStudent.getInstance();
 8        no2=IdnumberStudent.getInstance();
 9        System.out.println("学生学号号码是否一致：" + (no1==no2));
10        
11        String str1,str2;
12        str1=no1.getIdnumberStudent();
13        str2=no1.getIdnumberStudent();
14        System.out.println("第一次号码：" + str1);
15        System.out.println("第二次号码：" + str2);
16        System.out.println("***************************");
17        System.out.println("内容是否相等：" + str1.equalsIgnoreCase(str2));
18        System.out.println("是否是相同对象：" + (str1==str2));
19     }
20 }

Client.Java

 1 package tutorial7;
 2 
 3 public class IdnumberStudent {
 4     private static IdnumberStudent instance=null;
 5     private String no;
 6     
 7     private IdnumberStudent()
 8     {    
 9     }
10     
11     public static IdnumberStudent getInstance()
12     {
13         if(instance==null)
14         {
15             System.out.println("新生入学，分配学生学号！");
16             System.out.println("***************************");
17             instance=new IdnumberStudent();
18             instance.setIdnumberStudent("20195589");        
19         }
20         else
21         {
22             System.out.println("重复分配学号，获取旧号码！");  
23             System.out.println("***************************");
24         }
25         return instance;
26     }
27     
28     private void setIdnumberStudent(String no)
29     {
30         this.no=no;
31     }
32     
33     public String getIdnumberStudent()
34     {
35         return this.no;
36     }
37 }

IdnumberStudent.java

2、C++

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 class IdnumberStudent
 6 {
 7 private:
 8 
 9     static IdnumberStudent* student;
10     string no;
11     IdnumberStudent() {};
12 
13 
14     void setStudentNo(string no1)
15     {
16         no = no1;
17     }
18 
19 public:
20 
21     static IdnumberStudent* getStudent() {
22         if (student == NULL) {
23             cout << "新生入学，分配学生学号！" << endl;
24             cout << "***************************" << endl;
25             student = new IdnumberStudent();
26             student->setStudentNo("20194023");
27         }
28         else {
29             cout << "重复分配学号，获取旧号码！" << endl;
30             cout << "***************************" << endl;
31         }
32         return student;
33     }
34 
35     string getStudentNo() {
36         return no;
37     }
38 
39 };
40 
41 IdnumberStudent* IdnumberStudent::student = NULL;  //初始化 student
42 
43 int main() {
44     IdnumberStudent* no1, * no2;
45     no1 = IdnumberStudent::getStudent();
46     no2 = IdnumberStudent::getStudent();
47     if (no1 == no2) {
48         cout << "学生学号号码是否一致：true"<< endl;
49     }
50     else {
51         cout << "学生学号号码是否一致：false" << endl;
52     }
53     string str1, str2;
54     str1 = no1->getStudentNo();
55     str2 = no2->getStudentNo();
56     cout << "第一次号码：" + str1 << endl;;
57     cout << "第二次号码：" + str2 << endl;
58     cout << "***************************" << endl;
59     if (str1 == str2) {
60         cout << "内容是否相等：true" << endl;
61     }
62     else {
63         cout << "内容是否相等：false" << endl;
64     }
65     if (str1 == str2) {
66         cout << "是否是相同对象：true" << endl;
67     }
68     else {
69         cout << "是否是相同对象：false" << endl;
70     }
71     
72 }

Client.cpp

四、结果截图

1、Java结果截图

2、C++结果截图：

posted on 2021-10-09 19:59 桑榆非晚柠月如风阅读(5) 评论(0) 编辑收藏举报