Question

The multimap contains multimap<int,Questions*> map;. Im trying to get the map printing out using the following method:

Questions* Questions::printQuestion(int level)
{
    multimap<int, Questions*>::iterator it;
    pair<multimap<int, Questions*>::iterator,multimap<int, Questions*>::iterator> ret;

    ret = map.equal_range(level);
    if(ret.first != ret.second)
    {
    size_t sz = distance(ret.first, ret.second);
    size_t idx = rand() % sz;
    advance(ret.first, idx);
    it =ret.first;
    return (*it).second;
    }
    else
    {
        return NULL;
    }
}

But the method does nothing. Can anybody help me with this?

Answer 1

This function doesn’t print anything. It returns a Questions* that is randomly chosen from all questions with the given level. So if there are three questions with level 5, and you call printQuestion(5), you will get a pointer to a random question of those three. If you want to print the question that is chosen in this function, you will have to do something like so:

Questions* question = (*it).second;
std::cout << question->getText() << std::endl;

Replace getText() with whatever you need to do to print the question.

If you want the client that calls the function to print the question, you’ll do:

Questions* question = printQuestion(5);
std::cout << question->getText() << std::endl;

By the way, it’s not very common to name classes with the plural form. It’ll be easier to read your code if you class is called Question instead of Questions.