Question

I am having problems with the code bellow.

It can write fine if i kill the read section.
It can read fine if i kill the write section and the file has already been written.
The 2 don’t like each other. It is like the write stream is not closed… though it should be.

What is wrong?

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
using namespace System;

int main(array<System::String ^> ^args)
{
 string a[5];
 a[0]= "this is a sentence.";
 a[1]= "that";
 a[2]= "here";
 a[3]= "there";
 a[4]= "why";
 a[5]= "who";

 //Write some stuff to a file
 ofstream outFile("data.txt");     //create out stream
 if (outFile.is_open()){       //ensure stream exists
  for (int i=0; i< 5; i++){
   if(! (outFile << a[i] << endl)){    //write row of stuff
    cout << "Error durring writting line" << endl; //ensure write was successfull
    exit(1);
   }
  }
  outFile.close();
 }

 //Read the stuff back from the file
 if(!outFile.is_open()){  //Only READ if WRITE STREAM was closed.
  string sTemp;   //temporary string buffer
  int j=0;    //count number of lines in txt file

  ifstream inFile("data.txt");  
  if (inFile.is_open()){
   while (!inFile.eof()){
    if(! (getline(inFile, sTemp)) ){    //read line into garbage variable, and ensure read of line was
     if(!inFile.eof()){       //successfull accounting for eof fail condition.
      cout << "Error durring reading line" << endl; 
      exit(1);
     }
    }
    cout << sTemp << endl;  //display line on monitor.
    j++;      
   }
   inFile.close();
  }
  cout << (j -1) << endl;  //Print number lines, minus eof line.
 }

 return 0;
}

Answer 1

You have a memory overwrite.

You have six strings, but dimension only for five strings

 string a[5];
 a[0]= "this is a sentence.";
 a[1]= "that";
 a[2]= "here";
 a[3]= "there";
 a[4]= "why";
 a[5]= "who";

this can cause the rest of your program have unexpected behavior.