Anyone please explain what happens when we write Myclass res=obj1+obj2; I mean how the values are passed and how it works

Question

#include <iostream>
using namespace std;

class MyClass {
public:
int var;
MyClass() { }
MyClass(int a)
: var(a) { }

MyClass operator+(MyClass &obj) {
MyClass res;
res.var= this->var+obj.var;
return res;
}
};

int main() {
MyClass obj1(12), obj2(55);
MyClass res = obj1+obj2;

cout << res.var;
}

Answer 1

Myclass res = obj1+obj2 is similar to
Myclass res = obj1.operator+(obj2)
That means obj1 is used to call the function 'operator+' whereas obj2 is passed as an argument.