Question

Is this a good way to delete a map of longs and objects made with new

// iterate over the map
for (std::map<unsigned long, Object*>::iterator it = objects.begin(), it_end = objects.end(); it != it_end; ++it)
{
    Object* temp = it->second;
    if(temp)
        delete temp;
}

// clear the map
objects.clear();

Answer 1

Yes, although the better solution would be to use smart pointers instead of Object*, but that is a different subject.

You could shorten the content of the for to

{
   delete it->second;
}

delete null is defined and is a noop.