{Block that contains ' &operator ' and ' *this ' } // What are their roles?

Question

#include <iostream>
using namespace std;

class MyClass {
public:

MyClass&operator()(int a, int b) { // what is '&operator' used for?
x=a; y=b;
return *this;
}

void printInfo() {
cout << x << y;
}
private:
int x, y;
};

int main() {
MyClass obj;

obj ( 1 , 2 );

obj.printInfo();
return 0;
}

// outputs 12

It appears that ' return *this; ' returns both the values of x and y.
What does ' &operator ' do? Does it have to be paired with ' *this ' for the block to successfully return a value?
How come the output is the same with or without the '&' sign?

Answer 1

Myclass& operator ()(int a,int b)
Through this line you are implementing a concept called "operator overloading". Here you are overloading " () " operators. The "&" symbol simply means that the function will return object by reference which in this perticular case doesn't make any difference as you are returning a pointer.
Learn more about operator overloading here👇
http://www.cplusplus.com/doc/tutorial/templates/

The keyword "this" represents a pointer to the object whose member function is being executed. It is used within a class's member function to refer to the object itself.
Learn more about "this" pointer here👇
https://www.geeksforgeeks.org/this-pointer-in-c/