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This wont compile because the operator= returns void. The overloaded operator= has to return a reference to the current object in order for the copy constructor to assign a value to z.

The line A z = (a = b); is the only one that causes to print right?
So first it prints b and then it prints a (if A& is returned by = operator)

So the answer must be 2 3 1 2.
I do not understand how u guys got 2 2 1 1. Please explain.

The line

A(int ii , int jj) :i(ii),j(ii){}

is not clear. What is it doing?

I don't see any use of copy constructor here..

I tried in VC++,it can't compile with this "A z = (a = b)".Anyone has any idea what's wrong?

srini got the answer

If you make overloaded operator= return A& then, the above code will compile and you will indeed get "2211" as output, as marked by gevorg

arun, watchout j is initialized with ii too. i know its duh! but.. thats what they ask for.

Assuming they fix the copy constructor to return a self reference:

A a(1,2);
// 1 is assigned to a.i and to a.j because the constructor only uses the first parameter

A b(2,3);
// 2 is assigned to b.i and b.j
A z = (a = b);
// First, assignment operator is called, which outputs i and j of the passed in parameter (b) but does not change any values. Output is "22" and a reference to a is returned.
// Second, the copy constructor is called which only outputs the 1 and j values of the passed object (a). Output is "11"
// So the total output is "2211"

Assuming they fix assignment operator with A& instead of void

output will be "2222"

Here is complete program and explanation.

struct A
{
int i , j;
A(int ii , int jj) :i(ii),j(ii){}
A(const A&a)
{
cout << a.i << a.j;
}
A& operator = ( A& a)
{
cout <<a.i << a.j ;
return a;
}
};


int main(int argc, char **argv)
{
A a(1,2);
A b(2,3); ==> i and j value will be 2,2
A z = (a = b); ==> Here assignment operator will be called which will print 22. Now 'a' has b's values. then it will call copy constructor to which a object is passed which has value 22 .
}