Do I need to delete a pointer if I haven't assigned it a new value?

Question

Just a quick question:

Do I need to delete a pointer if I haven't actually assigned a new value to it?

What I've done if created a pointer and then handed it a reference to something like so:

Planet *planetPointer;

planetPointer = &earth;

Do I need to delete this pointer or can I just set it to null?

Mcburney

Only delete what you new. – Krafftebing

To be a little more pedantic than @chris: The rule is that for every new you should have a delete at some point, and for every new[] you should have a delete[] at some point. – Dasi

Duplicate - #12513926 – Retral

possible duplicate of C++ calling delete on variable allocated on the stack – Lake

Answer 1

You don't need to delete it, and, moreover, you shouldn't delete it. If earth is an automatic object, it will be freed automatically. So by manually deleting a pointer to it, you go into undefined behavior.

Only delete what you allocate with new.

Wootten

To put it another way: If you didn't new the object, you don't have ownership of it (unless relevant documentation says otherwise), and if you don't have ownership of it you shouldn't deallocate it. – Navarrete

Even worse, in a way, is when earth is a reference to a dynamically allocated object. Assuming that other author was a good citizen, that earth object will eventually be freed by the thing that allocated it. Delete it here and the program will fail on that later deletion. The reason this is nastier is because the error message makes it appears that the error is at the second delete. The author of the earth-allocating code will inevitable receive a nasty phone call or email saying "Your code is broken! It's dropping core." – Zephan