1 #ifndef USER.HPP
  2 #define USER.HPP
  3 #include<iostream>
  4 #include<string>
  5 using namespace std; 
  6 int BF(string S,string T);
  7 class User
  8 {
  9 private:
 10     string name;
 11     string password;
 12     string email;
 13     static int count;
 14 public:
 15     User(string
 
 n1):name(n1),password("111111"),email(""){++count;}
 16     User(string n1,string p1,string e1):name(n1),password(p1),email(e1){++count;}
 17     void set_email(string e1);
 18     void set_email();   
 19     void change_passwd();
 20     void print_info()const;
 21     static void print_n();
 22     ~User(){--count;};
 
 23 };
 24 int User::count=0;
 25 void User::set_email()
 26 {
 27     string e1;
 28     cout<<"Enter email address： ";
 29     cin>>e1;
 30     int i,flag=1;
 31     while(flag)
 32     {
 33         for(i=0;e1[i]&&flag;i++)
 34         {
 35             if(e1[i]=='@')
 36             flag=0
 
;
 37         }
 38         if(flag||!BF(e1,".com"))
 39         {
 40             cout<<"Invalid email address!Please enter again:";
 41             cin>>e1;
 42         }
 43     }
 44     email=e1;
 45     cout<<"Email is set successfully..."<<endl;
 46 }
 47 void User::change_passwd()
 48 {
 49     using namespace std;
 50     cout<<"Enter old password:";
 51     int i=1;
 52     while(i<4)
 53     {
 54         string p;
 55         cin>>p;
 56         if(p!=password)
 57         cout<<"Password input error.Please re-enter again:";
 58         else
 59         {
 60             cout<<"Enter new password: ";
 61             int flag=1;
 62             while(flag)
 63             {
 64                 int count=0;
 65                 cin>>p;
 66                 if(p.length()>=6)
 67                 {
 68                     for(int i=0;i<p.length();i++)
 69                     if(isdigit(p[i]))
 70                     count++;
 71                     if(count==p.length())
 72                     cout<<"Your password is too simple.Please re-enter again:";
 73                     else
 74                     flag=0;
 75                 }
 76                 else
 77                 cout<<"Your password is too short.Please re-enter again:";
 78             }
 79             password=p;
 80             cout<<"New password is set successfully..."<<endl;
 81             break;
 82         }
 83         i++;
 84     }
 85     if(i==4)
 86     cout<<"Please try after a while."<<endl;
 87 }
 88 void User:: print_info()const
 89 {
 90     using namespace std;
 91     cout<<"name:"<<name<<endl<<"password: ******"<<endl<<"email: "<<email<<endl;
 92 }
 93 void User::print_n()
 94 {
 95     if(count==0)
 96     cout<<"There is "<<count<<" user."<<endl;
 97     else
 98     cout<<"There are "<<count<<" users."<<endl;
 99 }
100 int BF(string S,string T)
101 {
102     int i=0,j=0;
103     while (i<S.length()&&j<T.length())
104     {
105         if(S[i]==T[j])
106         {
107             i++;
108             j++;
109         }
110         else
111         {
112             i=i-j+1;
113             j=0;
114         }
115     }
116     if(j==T.length())
117     return 1;
118     else
119     return 0;
120 }
121 #endif

 1 #include"User.hpp"
 2 #include<iostream>
 3 int main()
 4 {
 5     using namespace std;
 6     cout << "testing 1......" << endl;
 7     User user1("Tonny", "321321", "[email protected]");
 8     user1.print_info();
 9     cout << endl<< "testing 2......" << endl;
10     User user2("Conner");
11     user2.change_passwd();
12     user2.set_email();
13     user2.print_info();
14     User::print_n();
15 }

注意string型別的使用，使用前要新增usingnamespacestd;語句在巨集定義後面。