Vector subscript out of range error, C++

Question

When I try to run this program I get an error that halts the program and says, "Vector subscript out of range"

Any idea what I'm doing wrong?

#include <vector>
#include <string>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
using namespace std;

//(int argc, char* argv[]
int main()
{
    fstream bookread("test.txt");
    vector<string> words;

    bookread.open("test.txt");
    if(bookread.is_open()){
        cout << "opening textfile";
        while(bookread.good()){
            string input;
            //getline(bookread, input);
            bookread>>input;
            //string cleanedWord=preprocess(input);         
            //char first=cleanedWord[0];
            //if(first<=*/
            //cout << "getting words";
            //getWords(words, input);
        }
    }
    cout << "all done";

    words[0];

getchar();
}

Answer 1

You never insert anything into the words vector , so the line words[0]; is illegal, because it accesses the first element of it, which does not exist.

Answer 2

I don't see where you're pushing anything on to the vector. If the vector is empty, subscript 0 would be out of range.

Answer 3

It seems that your program never gets round to adding anything to the vector, usually done with push_back() , so at run-time words[0] produces your subscript out of range error.

You should check the size of the vector before accessing it.

Try this:

for(vector<string>::const_iterator it=words.begin(), end=words.end(); it!=end; ++it){
  cout << *it << ' ';
}

Answer 4

Can you please attach the version of the code where you actually push_back strings on the vector. Its not possible to debug the issue unless the code on which reproduce is available for review.