c++ - Doubts in a code to test the use of assignment operator -

i writing code test use of assignment operator , copy constructor. code follows:

#include <iostream> #include <algorithm> using namespace std;  class fun {   int i;   public:          fun():i(1) {i=1;cout<<"in: cons\n";}          ~fun() {cout<<"in: des\n";}          fun& operator=(fun b) {               cout<<"in: assignop\n";               swap(this->i, b.i);               return *this;          }          fun(fun& b) {               cout<<"in: copy cons\n";               b.i = this->i;          }          void print() {               cout<<i<<endl;          } };  main()  {    fun a;    fun b;    b = a;    a.print(); } 

and here output of code:

in: cons

in: cons

in: copy cons

in: assignop

in: des

-1216991244

in: des

in: des

now, there 2 things can't understand output.

firstly, why code going in copy constructor function? secondly, why value of 'i' being printed garbage instead of '1'?

i newbie excuse me if doubt obvious.

b = a; 

this causing assignment operator called. reason see copy cons in output because assignment operator takes argument value. a copied assignment operator function, requires copy constructor used.

both copy constructors , copy assignment operators take arguments const reference.

the reason garbage value because have line backwards:

b.i = this->i; 

it should be:

this->i = b.i; 

otherwise, copy constructor copies indeterminate value of this->i object copying from.