Question

Ok guys this problem has been bugging me all day and I cant seem find a solution. I know Its a long post but I would be very grateful for any help you can offer.
I am working on a chatbot program that reads in from a .dat file to populate a library of keywords. Taking an object orientated approach I defined a class called “Keyword”, the class definition is shown below:

class Keyword
{
public:   
    //_Word holds keyword 
    vector<string> _Word;
    //_Resp holds strings of responses
    vector<string> _Resp;
    //_Antymn holds words that are the opposite to keyword
    vector<string> _Antymn;

    // Constructor
    Keyword()
    {
        // Clears members when new instance created
        _Word.clear();
        _Resp.clear();
        _Antymn.clear();
    }
};

Therefore every time a new keyword is found in the .dat file, a new instance of the class keyword must be created. To store all these instances of keyword I create another vector but this time of type Keyword and call it library:

typedef vector<Keyword> Lib;
Lib library;// this is the same as saying vector<Keyword> library

Now this is the problem I have: After a user inputs a string I need to check if that string contains a keyword from the library i.e. I need to see if the string in _Word appears in the user input. Looking at it from a hierarchy of vectors you have:

The top level --> libary //*starting point
                 --> Keyword
                    --> _Word
                      -->"A single string" <-- I want to reference this one
                    --> _Resp
                      -->"Many strings"
                    --> _Antymn
                      -->"Many strings"

Phew! I hope that made sense.
This is the code I started to write:

size_t User::findKeyword(Lib *Library)
{
    size_t found;
    int count = 0;

    for(count = 0; count<Library->size(); count++)
    {
      found = _Input.find(Library->at(count)); // this line needs to reference _Word from each keyword instance within library
      if(found!= string.npos)
        return found;
    }

    return 0;
}

I have also tried to use the “operator[]” method but that doesnt seem to do what I want either.
Does anyone have any idea ? I would be very suprised if it couldn’t be done. Thank you in advance.

Answer 1

You have to change your code to this:

for(count = 0; count<Library->size(); count++)
{
    for(int j = 0; j < Library->at(count)._Word.size(); ++j){
        found = _Input.find(Library->at(count)._Word[j]);
                                              ^^^^^^^^^
        if(found!= string.npos)
             return found;
    }
}

in order to access the member variable and to iterate through your vector of strings. Library->at(count) is an object of class the Keyword.
I assume that _Input.find() takes a string as argument.

If your Keyword instance stores just one keyword, you might as well change it to string _Word, so that you wold not need the second loop.

for(count = 0; count<Library->size(); count++)
{
    found = _Input.find(Library->at(count)._Word);
    if(found!= string.npos)
        return found;
}

And to enforce the other comments: you should not use the preliminary _-underscore in your variable names since they are reserved by the implementation.