Thread: C++ Classes and Vectors help

I recently took my C++ midterm, and I want to make sure I know how to do the things that it asked me to do. Can some people help explain to me how this would be done?

Create a class Tweet with a constructor, accessor, and mutator functions where Tweet accesses strings Subject and Message, and a mutator that appends subject to message.

I think i know how to do this part

Code:

class Tweet
{
Public:
Tweet();
Tweet(string subject, string message);//constructor
Tpend(string subject, string message);
Private:
string subject;
string message;
}

This probably isn't right, can someone help me with creating a class, specifically this one?

Then it asked to create the functions for the class. I think i know how to do this one, but then again I may be wrong:

Code:

Tweet::Tweet()
{
this->subject = subject;
this->message = message;
}

Tweet::Tweet(string subject, string message)
{
}

Tweet::Tpend(string subject, string message)
{
message = subject + ' ' + message;
}

The other part of the question was to create an int main using tpend and addTweet (from a class it gave) to add a message with it's subject inside vector v.

Code:

int main()
{
string mess = "Hello!";
string subj = "Twitter";
Tweet t(subj, mess);
t.Tpend(subj, mess);
vector<string>v;
t.addtweet(mess, v);
}

addTweet just does a simple v.push_back(message);

I know this is a lot I'm asking, but just some help would be great! Thanks =)

You might want to check the part you think you know, before progressing to the subsequent bits.

An accessor is a member function that retrieves the value of something, and a mutator is a member function that changes the value. Such functions are not generally constructors though.

your class Tweet should look something like this

Code:

class Tweet
{
public:
    Tweet();
    Tweet(string subject, string message);//constructor
    string Tpend(string subject, string message);
    string getSubject();
    void setSubject(string subject);
    //do same for message
    void addTweet(string message, vector<string> *v);
private:
    string subject;
    string message;
};

then for your class members etc... (might be a bit crowded but u can space it out)

Code:

Tweet::Tweet() : subject(""), message("") {}
Tweet::Tweet(string subject, string message) : subject(subject), message(message) {}
string Tweet::Tpend(string subject, string message) { return (subject + " " + message); }
string Tweet::getSubject() { return this->subject; }
void Tweet::setSubject(string subject) { this->subject = subject; }
void Tweet::addTweet(string message, vector<string> *v) { v->push_back(message); }

quick example of how to use it

Code:

int main(int argc, char * argv[])
{
    Tweet t("Hello", "World =D");
    cout << t.getSubject();
    vector <string> vect;
    t.addTweet("Add this", &vect);
    cout << endl << vect[0];
    return 0;
}

Why didn't you place a vector in your class so that it'll store all of your tweets or messages instead of having an external one?