Question

If I declare and object inside a for, and for example assign it’s adress to a pointer, when that for ends, would that pointer be pointing to invalid memory? Like it happens at the end of a method with the objects that you declared in that method

Answer 1

Yes, and not just inside for – inside any block.

For example:

 void bar()
 {
   foo* p;
   {
     foo f;
     p = &f;
   }
   // p no longer points to a valid object, f has ended its lifetime

Same thing with for except that the object will be created/destroyed each time the loop runs.

Now, if instead you have:

 void bar()
 {
   foo* p;
   {
     foo* f = new foo;
     p = f;
   }
   // p is still valid here, you need to clean up yourself with delete

And if you do that inside a for, you’ll need to be very careful not to leak all those allocations.