Question

i am using an empty vector of structs.

now, when i am entering data to one of the struct members, does it change the size of the vector?

if yes, how should i initialize the iterator?
i have a runtime error, and my guess is that my iterator is invalid.

some relevant code:

   struct wordstype
{
    string word;
    int counter_same;
    int counter_contained;
    int counter_same1;
};
 std::vector<wordstype>::iterator iv=vec1.begin();
string temp_str;
string::iterator is=str1.begin();

while (is!=str1.end())
{
    if (((*is)!='-')&&((*is)!='.')&&((*is)!=',')&&((*is)!=';')&&((*is)!='?')&&((*is)!='!')&&((*is)!=':'))
    {
        temp_str.push_back(*is);
        ++is;
    }
    else
    {        
        (*iv).word=temp_str;
        ++iv;
        str1.erase(is);
        temp_str.clear();
    }
}

Answer 1

Changing values of the struct members doesn’t affect the size of the vector. You get a run-time error, because you’re trying to access the first element of an empty vector.

Try this instead:

wordstype wt;       // create a new struct
wt.word = temp_str; // set its elements as desired
vec1.push_back(wt); // insert the new struct into the empty vector

Alternatively you can declare the vector as

vector<wordstype> vec1(1);

which would initialize it with size 1. Then your current code will work (somewhat).