access a variable by reference from a class in c++

Question

I have a class in c++ a portion of which is below

class Node{
    public:
       vector<string> getNames() const;
    private:
        vector<string> names_;
};
vector<string> Node::getNames(){
    return names_;
}

the function getNames() passes a copy of the vector. How can i modify my class so that i can reference the vector 'by const reference' from any other class that i declare the Node object instead of passing a copy?

Answer 1

Change the definition to

const vector<string>& getNames() const;

Answer 2

Try this:

class Node
{
    public:
       const vector<string>& getNames() const;

    private:
        vector<string> names_;
};

const vector<string>& Node::getNames() const
{
    return names_;
}

Few things:

1. getNames() is now a const method, because the Node does not logically change.
2. Return as a constant reference, so you don't make a copy.