• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 260
  • Last Modified:

Problem reading text file and assign to array of object. Please help.

My program always read more than three records and in my array, all records are same with last record.  Please help me to find out the problem.  Thanks first...

(check the loadData() method)

text file data; STUDENT, user1 and pass1 consider as on record, store in one account object.

STUDENT
user1
pass1
LECTURER
user2
pass2

the accountList contain more than 2 records.  when i displayed it, all is last records.
LECTURER
user2
pass2
LECTURER
user2
pass2
LECTURER
user2
pass2
.
.

I tried to assign directly to array..
accountList[getNoOfAcc()].setUserType(tType);
still the same.

class Account{
private:
  char *userType;
  char *userID;
  char *userPassword;
public:
  //getters and setters
}

class Bookshop{
private:
  Book bookList[arraySize];
  BookOrdered orderList[arraySize];
  BookRecommended recommendList[arraySize];
  Account accountList[arraySize];

  char *typeOfUser;
  char *id;
  int noOfAcc;
  int noOfBook;
  int noOfOrderBook;
  int noOfRecommendBook;
public:
  //setters
  void setID(char* tID){
    id=tID;
  };
  void setTypeOfUser(char* tType){
    typeOfUser=tType;
  };

  void setNoOfAcc(int tNoOfAcc){
    noOfAcc=tNoOfAcc;
  };

  Account getAccount(int index){
    return accountList[index];
  }
  void setAccount(Account aAccount, int index){
    accountList[index];
  }
  int getNoOfAcc(void){
    return noOfAcc;
  };  
  void setNoOfAcc(int tNoOfAcc){
    noOfAcc=tNoOfAcc;
  };
  void addAccount(Account aAccount, int index){
    accountList[index]=aAccount;
  };
}



void Bookshop::loadData(void){
  FILE *readFile;
  char* tType=new char[100];
  char* tID=new char[100];
  char* tPassword=new char[100];

  Account aAccount;
  setNoOfAcc(0);
   //read account
   readFile=fopen("c:\\account.txt", "r+");
   if(readFile==NULL){
     cout<<"Error reading account file..."<<endl;
     getch();
     exit(1);
   }
   while(!feof(readFile)){
     Account aAccount;
     fscanf(readFile,"%s",tType);
     aAccount.setUserType(tType);

     fscanf(readFile,"%s",tID);
     aAccount.setUserID(tID);

     fscanf(readFile,"%s",tPassword);
     aAccount.setPassword(tPassword);
     cout<<"NoOFAcc="<<getNoOfAcc()<<endl;getch();

     addAccount(aAccount,getNoOfAcc());
     setNoOfAcc(getNoOfAcc()+1);
   };
   fclose(readFile);

  //test
   cout<<"No of account "<<getNoOfAcc()<<endl;
     clrscr();
     for(int loop=0;loop<getNoOfAcc();loop++){
       aAccount=getAccount(loop);
       cout<<"TYPE="<<aAccount.getUserType()<<endl;
       cout<<"ID="<<aAccount.getUserID()<<endl;
       cout<<"Password="<<aAccount.getPassword()<<endl;
     };
     getch();
};

0
yongyih
Asked:
yongyih
  • 5
  • 4
1 Solution
 
jkrCommented:
The problem is that you are using pointers and you are overwriting them - use

#include <string.h>

class Bookshop{
private:
 Book bookList[arraySize];
 BookOrdered orderList[arraySize];
 BookRecommended recommendList[arraySize];
 Account accountList[arraySize];

 char *typeOfUser;
 char *id;
 int noOfAcc;
 int noOfBook;
 int noOfOrderBook;
 int noOfRecommendBook;
public:
 //setters
 void setID(char* tID){
   id= strdup ( tID);
 };
 void setTypeOfUser(char* tType){
   typeOfUser= strdup (tType);
 };

// ...

};

Of course, you'll have to 'free()' the memory when you are done.

instead
0
 
yongyihAuthor Commented:
To jkr,

  thank you thank you... when display, can display first record already.  But why program read extra record, which is same as the last one in text file?

STUDENT
user1
pass1
LECTURER
user2
pass2
LECTURER
user2
pass2

is it my checking for EOF has problem??

i have another 3 class in the program.  Does it mean every setter has to use strdup??

thanks a lot!!!!

0
 
jkrCommented:
>>Does it mean every setter has to use strdup??

Actually, if you wanna go with char*, yes, you will. What about using STL strings?
0
Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

 
yongyihAuthor Commented:
Its ok for using strdup.  i just changed all the setters to strdup(..)

Now only remain two problems.
1. how to free the memory?
char* name=new char[256];
like this?
name=NULL;

2. Why need extra record?  
Is it because my text file has extra line

STUDENT
user1
pass1
LECTURER
user2
pass2
->cursor stop there.

this is the reason?  
0
 
yongyihAuthor Commented:
but when i delete the extra line, save it.  when i edit it again, the extra line come out automatically...

please help me. thanks. ^_^
0
 
yongyihAuthor Commented:
Thank you very much ! =)
0
 
jkrCommented:
>>1. how to free the memory?
>>char* name=new char[256];
>>like this?
>>name=NULL;

No - everything that was allocated by "new[]" has to be deallocated using "delete[]" in your case

delete [] name;

NOTE that the strings duplicated by "strdup()" have to be released using "free()"

>>2. Why need extra record?  
>>Is it because my text file has extra line

This is probably the reason, as you check "feof()" - which makes your program assume that there still is a full record to read, even though it is just a Carriage Return.




0
 
yongyihAuthor Commented:
my program works correctly now. just that cannot read book name that has a space ("Book Name") will read as Book and Name..but never mind. ^_^

free().. where should i used it?
because i used strdup() and assign directly to object..
never mind.. as long as no errors =)

thanks..
0
 
jkrCommented:
>> free().. where should i used it?

The best way for this would be in the destructors of your classes, e.g.

class Bookshop{

public:

 Bookshop () { typeOfUser = id = NULL;}
 ~Bookshop () { free ( typeOfUser); free ( id);}

// ...
};
0

Featured Post

Vote for the Most Valuable Expert

It’s time to recognize experts that go above and beyond with helpful solutions and engagement on site. Choose from the top experts in the Hall of Fame or on the right rail of your favorite topic page. Look for the blue “Nominate” button on their profile to vote.

  • 5
  • 4
Tackle projects and never again get stuck behind a technical roadblock.
Join Now