C++ Reading Characters from Text File to Dynamically Allocated Array

Question

I am relatively new to C++, and I am attempting to read sequenceofchars from a text file into a char array that is dynamically allocated. My code is as follows:

while (file.get(c))
{
    if (c =='\n')
        continue;

    char *temp = new char[i++];
    arrayA = new char[i++];
    arrayA[i] = c;
    delete [] arrayA;
    arrayA = temp;
}

And the text file format is as follows:

>NameOfChars
sequenceofchars

This is obviously horribly broken, but I've struggled to figure out the exact methodology one would use to go through this. I know about the Vector class, but I am unsure about how to go about using that if that is the preferred method for reallocating arrays on the heap. Any help would be greatly appreciated. Thank you.

score 1 · Accepted Answer · answered Nov 16 '14 at 18:20

1

I think you should definitely take a look at the vector class since it would make your code a lot cleaner. Here is a small (untested) code sample of how to use it:

#include <vector>

std::vector<char> my_vector;

while (file.get(c))
{
    if (c =='\n')
        continue;

    my_vector.push_back(c);
}

For more information please check http://www.cplusplus.com/reference/vector/vector/push_back/

answered Nov 16 '14 at 18:20

Hanna H

120
7

Would I be able to convert the vector to a char array in the end? – tdark Nov 16 '14 at 18:30
Yes you can: http://stackoverflow.com/questions/2923272/how-to-convert-vector-to-array-c – Hanna H Nov 16 '14 at 18:36

score 0 · Answer 2 · answered Nov 16 '14 at 18:19

0

A raw array isn't dynamically allocated; hence using an STL container like vector would be better.

ifstream inf;
char c;
vector<char> charVec;

while (inf >> c)
{
    charVec.push_back(c);
}

answered Nov 16 '14 at 18:19

Poriferous

1,566
4
20
33

C++ Reading Characters from Text File to Dynamically Allocated Array

2 Answers2