How do you overload the '<' operator to compare between objects of the same class?

Question

Right now I have a class item

   class Item{
        public:

            short p;        //profit
            short w;        //weight
            bool *x;        //pointer to original solution variable
            void set_values (short p, short w, bool *x);

    };

and I need to compare two different instances so that it checks the values of each one and returns either true/false

 if (Item a < Item b){
       //do something
 }

How can I do that? I've been reading cppreference but I don't really understand how to do it.

Answer 1

Very simply,

bool Item::operator<(const Item& other) const {
    // Compare profits
    return this->p < other.p;
}

Answer 2

To compare both the left hand side p and w with the right hand side p and w use the following code:

class MyClass
{
public:
    short p;
    short w;
    friend bool operator<(const MyClass& lhs, const MyClass& rhs)
    {
        return lhs.p < rhs.p && lhs.w < rhs.w;
    }
};

Answer 3

For example, if you want to compare p, the code should look like this:

class Item {
private:
...
public:
    friend bool operator < (const Item& lhs, const Item& rhs) {
        return lhs.p < rhs.p;
    }
};