Is this piece of C++ considered okay in terms of memory management?

Question

I am kind of getting bogged down by the concept of memory management (all my previous programming languages doesn't need me to manage the memory). I'm not sure if creating a variable will consume memory if I don't destroy it later.

#include <math.h>
#include <iostream>
using namespace std;

double sumInfiniteSeries(double u1, double r){
 return u1 / (1 - r);
}

double sumInfiniteSeries(double u1, double r, bool printSteps){
 if (printSteps){
  double lastTotal;
  double total = 0.0;
  double sn = u1;
  for (int n=1;n<=1000;n++){
   lastTotal = total;
   total += sn;
   sn *= r;
   cout <<  "n = " << n << ": " << total << endl;
   if (fabs(lastTotal - total) < 0.000000000000001) return total;
  }
  return total;
 } else {
  return sumInfiniteSeries(u1, r);
 }
}

Do i need to "destroy" any variables in these 2 functions?

Edit: So when I create my own class and its instance would I need to start memory management?

Answer 1

What memory management? You’re only using the stack here, no memory management needed.

Manual memory management comes into play when you fiddle with new and delete.

Answer 2

As long as you stay away from new and especially delete, there is nothing to worry about w.r.t. memory management in C++.

If you do encounter a situation where you need to manually allocate some memory with new, the best thing you can do is to immediately hand the responsibility for that memory over to a smart pointer class, like auto_ptr<T>, unique_ptr<T>, shared_ptr<T>, etc.. Assuming you use the one with the right semantics, they will ensure the memory gets released at just the right time.