Thread: Memory problem with structure and strings

I've searched for some solutions and tried some different variations, but I'm having a lot of trouble assigning a value to a string in a structure. I'm using the following structure:

Code:

struct database
    {
        string name;
        string site;
        int coun;
    }data[4557];

string holder;
string first = "<1>";
i = 0;

while(getline(calibrate, holder))
{
        if (!holder.find(first, 0))
        {
            holder.erase(0, 3);
            data[i].name = holder;
            ++i;
        }
}

Running valgrind shows that the problem occurs at the line where data[i].name is assigned the value of holder, specifically that there is an uninitialized value starting when main() is declared.
Do I need to allocate memory for name, site, and coun when I declare them? What exactly is going on here?

This is the simplified program

Code:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream calibrate ("withrefm");
    if (!calibrate.is_open())
    {
        cout<<"Error opening file\n";
    }


    struct database
    {
        string name;
        string site;
        int coun;
    }data[4557];

    int i;
    string first = "<1>";
    string holder;

    //enzyme* enz = new enzyme[4557]; // current structure can handle up to 4557 enzymes at once

    i = 0;
    while(getline(calibrate, holder))
    {
        if (!holder.find(first, 0))
        {
            holder.erase(0, 3);
            data[i].name = holder;
            ++i;
        }

return 0;
}

Thanks for the advice, turns out that I simply needed to make i < 4557 another condition of the while loop. Now it works perfectly.