Clarification on operator overloading

I am just starting out a course in C++ programming at university, and I've been given this line of code in a header file named Card.h:

Code:

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bool operator < (const Card& rhs) const;

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I'm meant to be writing an accompanying Card.cpp, but I don't quite understand what's going on in this line, so I was hoping that someone might be able to help. I know that rhs is a reference to a Card object, but is it meant to be comparing to something?

Thanks in advance for your help!

That is an example of overloading the "<" operator. What you are comparing is the current object against the passed reference. Your implementation would look something like:

Code:

---

bool Card::operator < (const Card& rhs) const
{
  if(this->data < rhs.data)
      return true;
  else
      return false;
}

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The point is to compare two instances of the Card class. Then is can be used as follows:

Code:

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Card c1;
Card c2;
if(c1 < c2)
  // do something...

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Thanks so much, that explained everything. :)

Although one might implement it more like:

Code:

---

bool Card::operator < (const Card& rhs) const
{
  return this->data < rhs.data;

  //if(this->data < rhs.data)
  //  return true;
  //else
  //  return false;
}

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