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c++pointersvectorc++17

Does `std::cout << &i <<` print address of `i` or address of each element in num?

#include <iostream>
#include <vector>

int main ()
{
    std::vector<int> num {1, 2, 3};
    for (const int &i : num)
    {
        std::cout << i <<"\n";
        std::cout << &i <<"\n";
    }
 }
Solution

  • The variable i is a reference, not an object. This is a bit of a special thing in C++. References are not objects, and so there is no such thing as "the address of i" as you're asking. The value of expression i, in which you name the reference, is the object which is bound to the reference. Therefore, &i is the address of the vector element. (You should see the address values increasing arithmetically, since the vector stores elements contiguously.)

    If you wanted to see the address of a local variable, you could change i to be an object variable, like this:

    for (int i : num)
{
    std::cout << i << "\n";
    std::cout << &i << "\n";
}