Why do I get weird values after reading from file into array?

Question

I am pretty novice at C++. Basically what I am trying to do is to read a file into any array and display it, but what happens is that a garbage values appears when running the code below. What exactly I am missing?

#include "stdafx.h"
#include<iostream>
#include<fstream>

using namespace std;

void main() {
    int array_size = 1024;
    char*array = new char[array_size];

    int position = 0;
    ifstream fin("Map.txt");
    if (fin.is_open()) {
        while (!fin.eof() && position < array_size) {
            fin.get(array[position]);
            position++;
        }
        array[position - 1] = '\0';

        cout << "Displaying array......" << endl << endl;

        for (int i = 0; array[i] != '0'; i++) {
            cout << array[i];
        }
    } else {
        cout << "File could not be opened" << endl;
    }
}

[why while(!feof()) is always wrong](http://stackoverflow.com/questions/5431941/while-feof-file-is-always-wrong) — Barmar, Oct 23 '15 at 16:31
`char[array_size];` this is already using c++ extensions, the array size must be a constant expression. — Ryan Haining, Oct 23 '15 at 16:31
`array[i] != '0'` what is the significance of this condition? — Ryan Haining, Oct 23 '15 at 16:33
You have a typo. `array[i] != '0'` needs to be `array[i] != '\0'`. — R Sahu, Oct 23 '15 at 16:33
I am not getting an error, I am getting a garbage values filling out the array in the output — haitham hany, Oct 23 '15 at 16:36
well thanks all I guess I had a typo that I didn't notice :/ writing '0' instead of '\0' — haitham hany, Oct 23 '15 at 16:37
you aren't deleting `array` anywhere, but really you should be using `std::vector array(array_size);` — Ryan Haining, Oct 23 '15 at 16:58

score 1 · Answer 1 · answered Oct 23 '15 at 16:37

1

The main issue is that your for loop condition is wrong. You should not be comparing array[i] against '0' because that is the ASCII character 0 whose value is actually 48.

You want to compare array[i] against the "null-terminating character" which is '\0' whose value is 0.

answered Oct 23 '15 at 16:37

Mohamad Elghawi

2,071
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14

Problems that can be resolved by fixing a typo should not be answered. They are not useful to anybody else. They need to be closed. – R Sahu Oct 23 '15 at 16:46

Why do I get weird values after reading from file into array?

1 Answers1