What is purpose of a “this” pointer in C++? [duplicate]

Answer 1

For example if you write an operator=() you must check for self assignment.

class C {
public:
    const C& operator=(const C& rhs)
    {
        if(this==&rhs) // <-- check for self assignment before anything
            return *this;
        // algorithm of assignment here
        return *this; // <- return a reference to yourself
    }
};