Question

Look at the code below. I know it doesn’t return the address of local variable, but why does it still work and assign the variable i in main() to ‘6’? How does it only return the value if the variable was removed from stack memory?

#include <iostream>

int& foo()
{
    int i = 6;
    std::cout << &i << std::endl; //Prints the address of i before return
    return i;
}

int main()
{
    int i = foo();
    std::cout << i << std::endl; //Prints the value
    std::cout << &i << std::endl; //Prints the address of i after return
}

Answer 1

You got lucky. Returning from the function doesn’t immediately wipe the stack frame you just exited.

BTW, how did you confirm that you got a 6 back? The expression std::cout << &i ... prints the address of i, not its value.