Question

im struggling with this part of code , no matter what i try i cant get it to read into a record after two lines

the text file contains

Mickey Mouse 
12121
Goofy
24680
Andy Capp
01928
Quasi Modo
00041
end

and the code is

#include<iostream>
#include<string.h>
#include <stdio.h>
#include <windows.h>
#include<iomanip>
#include<conio.h>
#include<fstream>
#include<string>
using namespace std;

struct record          
{               
char name[20];
int number;
 };



void main()
{


record credentials[30];
    int row=0; 
fstream textfile;//fstream variable
textfile.open("credentials.txt",ios::in);
textfile.getline (credentials[row].name,30);
//begin reading from test file, untill it reads end
while(0!=strcmp(credentials[row].name,"end"))
{ 

    textfile>>credentials[row].number;

    row++;
    //read next name ....if its "end" loop will stop
    textfile.getline (credentials[row].name,30);
}
textfile.close();

}

the record is only taking the first two lines and the rest is empty
any ideas ??

Answer 1

The problem is that:

textfile>>credentials[row].number;

while not consume the newline character. The subsequent call to textfile.getline() reads a blank line and the next:

textfile>>credentials[row].number;

attempts to read "Goofy" into an int which fails and set the failbit of the textfile stream meaning all further attempts to read fail. Check the return value to detect failure:

if (textfile >> credentials[row].number)
{
    // Success.
}

I am not entirely sure how the program ends as "end" will never be read but I suspect it ends abnormally as there is no mechanism to prevent overruning the end of the credentials array (i.e no row < 30 as part of the loop terminating condition).

---

Other:

• Instead of using a fixed sized char[] to read the names into you can use std::getline():

  #include <string>
  
  struct record
  {
      std::string name;
      int number;
  };
  
  if (std::getline(textfile, credentials[row].name))
  {
  }
  

• Instead of using a fixed sized record[] you could use a std::vector<record> which will grow as required.