Question

/* simple class that has a vector of ints within it */
class A
{
public:
   vector<int> int_list;
};

/* some function that just returns an int, defined elsewhere */
int foo();

/* I want to fill the object's int_list up */
A a_obj;

int main() {
   for (int i = 0; i < 10; i++) {
      int num = foo();
      a_obj.int_list.push_back( num );
   }
}

Is the scope of num limited to the for loop? Will it be destroyed once the for loop is exited? If I try to access the numbers in a_obj‘s int_list will I not be able to as the numbers inside will have been destroyed?

Answer 1

Is the scope of num limited to the for loop?

Yes

Will it be destroyed once the for loop is exited?

It’ll be destroyed after each iteration, and then created again for the next!

If I try to access the numbers in a_obj‘s int_list will I not be able to as the numbers inside will have been destroyed?

Containers store copies, so you don’t have to worry about this.

You only run into these sorts of issues with references and pointers.