Need help with vector writing in/out. I've been working for hours!!

f00tiefan (21)
Here is my code. This part works. It accepts the string and writes it to the file

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#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <cmath>
using namespace std;

class UserPw
{
 public:
 UserPw(string u, string p);
 string getUser(); 
 string getPassword(); 
 
 private :
 string user;
 string password;
};

UserPw::UserPw(string u, string p)
{
 user = u;
 password = p;
}

string UserPw::getUser()
{
 return user;
}

string UserPw::getPassword()
{
 return password;
}



class PasswordFile
{
 public:
 PasswordFile(string f);
 vector<UserPw> getFile();
 void addpw(UserPw newentry);
 void WriteToFile();
 bool checkpw(UserPw entry);
 void updatepw(UserPw entre, string newpass);
 void deletepw(UserPw entre);

 private:
 string filename;
 vector<UserPw> entry; 
};


PasswordFile::PasswordFile(string f)
{
 filename = f;
 fstream infile;
 infile.open(filename.c_str());
 string u,p;
 infile >> u >> p;
  while(infile.good())
  {
    entry.push_back(UserPw(u,p));
    infile >> u >> p;
  }
 infile.close();
}

vector<UserPw> PasswordFile::getFile()
{
 return entry;
}

void PasswordFile::WriteToFile()
{
  fstream outfile;
  outfile.open(filename.c_str());
    for (int i=0; i < entry.size(); i++)
   {
     outfile <<entry[i].getUser() << " " << entry[i].getPassword() <<"\n";
   }
  outfile.close();
}

void PasswordFile::addpw(UserPw newentry)
{
 entry.push_back(newentry);
 this -> WriteToFile();
}

int main()
{
 PasswordFile passfile("password.txt");
 passfile.addpw(UserPw("dbotting","123qwe"));
 passfile.addpw(UserPw("egomez","qwerty"));
 passfile.addpw(UserPw("tongyu","liberty"));
 passfile.addpw(UserPw("omurphy", "bruins"));
}


I can't get these instructions to work, I've been working on it for hours.

1. bool checkpw(UserPw entry)
This function accepts a username/password combination and checks the entry in the PasswordFile object. If the username/password combination matches that in the PasswordFile object, the function returns true. Otherwise it returns false.

2. void updatepw(UserPw updateentry)
This function accepts a username/password combination and changes the entry with the username to the password provided in updateentry. For example, if updateentry has the username/password values John/cat, then updatepw will change the password for John to cat. Don't forget to write the updated information to the file.

3. void deletepw(UserPw deleteentry)
This function accepts a username/password combination and deletes the entry with the provided username. For example, if deleteentry has the username/password values John/cat, then deleteentry will delete the entry with the username John. (The password part is ignored.) Again, don't forget to write the updated password information to the file. 

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bool PasswordFile::checkpw(UserPw entry)
{
for (int i=0; i< entry.size; i++) 
  {
    if (entry[i].getUser() = entry[i].getUser())
    {
     if(entry[i].getPassword() = entry[i].getPassword())
     {
     return true;
     }
    }
  }
 return false;
}

 void PasswordFile::updatepw(UserPw entre, string newpass)
{
 for(int i = 0; i < entry.size(); i++)
  {
  if (entry[i].getUser() == entre[i].getUser())
    {
     if(entry[i].getPassword() == entre.getPassword())
     {
      this -> deletepw(entre);
      this -> addpw(UserPw(entre.getUser(), newpass));
      this -> WriteToFile();
     }
    }
   }
}

void PasswordFile::deletepw(UserPw deleteentry)
{
 entry.push_back(deleteentry);
 this -> WriteToFile();

 for(int i = 0; i < entry.size(); i++)
 {
  if (deleteentry[i].getUser() == entry[i].getUser())
    {
     if(entry[i].getPassword() == entry[i].getPassword())
     {
      (entry[i] == entry.size() - 1);
       entry.pop_back();
       this -> WriteToFile();
     }
    }
  }
}
Last edited on
coder777 (8450)
Well

This makes things easier
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class UserPw
{
...
  bool operator==(const UserPw &upw) const // Note: const UserPw &upw avoids copy
  {
     return ((upw.user == user) && (upw.password == password));
  }
...
};

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bool PasswordFile::checkpw(UserPw upw) // Note: better const UserPw &upw
{
for (int i=0; i< entry.size; i++) 
  {
    if (upw == entry[i])
     return true;
  }
 return false;
}
alternatively
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include <algorithm>
...
bool PasswordFile::checkpw(const UserPw &upw)
{
  return (std::find(entry.begin(), entry.end(), upw) != entry.end()); // Note: use of bool operator==(const UserPw &upw) const 
}
Not tested but still...
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