When do you need to delete C-style arrays?

Question

I was reading an excellent answer to another question which gave these specific examples:

char[] array = {'a', 'b', 'c', '\0'};

Thing* t = new Thing[size];
t[someindex].dosomething();

I commented that, as good practice, you should add delete[] to the second example, as this is the bit people forget leading to memory leaks.

But I can't remember if you need to delete[] in the first instance. I don't think you do, because there's no new so it's on the stack, but I'm not 100% sure that's right.

Answer 1

I don't think you do, because there's no new so it's on the stack, but I'm not 100% sure that's right.

This reasoning is correct when the array is defined inside a function, and is therefore on the stack. You must never use delete on any objects that have been created on the stack without the use of new. Using delete on stack allocated objects will lead to undefined behavior.

If the definition char[] array = {'a', 'b', 'c', '\0'}; appeared at file scope, however, it will have static storage duration and will not be on the stack, but it still won't have been dynamically allocated and still must not be delete[]d.

So, either way, don't delete[] the array....