Const references - C++

Question

I had a doubt regarding the concept of const references in C++.

int i =10;   
const int &j = i;  
cout<<"i="<<i<<" j:"<<j; // prints i:10 j:10

i = 20;
cout<<"i="<<i<<" j:"<<j;  // prints i:20 j:10 

Why second j statement doesn't print the new value i.e 20.

How it is possible if references to any variable denotes strong bonding between both of them.

Answer 1

That is a compiler bug. The code should print 20 20.

Answer 2

I don't see any reason why j wouldn't print 20 in the second cout.

I ran this code :

int main() {
        int i =10;   
        const int &j = i;  
        cout<<"i="<<i<<" j:"<<j << endl; // prints i:10 j:10

        i = 20;
        cout<<"i="<<i<<" j:"<<j << endl;  // prints i:20 j:10 
        return 0;
}

And it gave me this output:

i=10 j:10
i=20 j:20

See the online demo yourself : http://ideone.com/ELbNa

That means, either the compiler you're working with has bug (which is less likely the case, for its the most basic thing in C++), or you've not seen the output correctly (which is most likely the case).