Heap vs Stack allocation

Question

I am alittle bit confused on topic of allocating objects on heap vs allocating on stack, and when and how delete() should be called.

For example I have class Vector.

Answer 1

1. delete [] v; - it's an array notation of delete operator. You have to use it when deleting arrays, instead of deleting each element sequentially.
2. Vector* v = Vector[100]; just won't compile. Write Vector v[100]; and it will allocate array of vectors on stack. You may not delete it manually.
3. x, y, z are on the heap as the whole object is on the heap
4. items[10] is also allocated on the heap as is makes part of the object. To delete it just call delete v2;. You don't need a special destructor unless you allocate anything in constructor.
5. int* items; is stored on the stack as it's part of the object allocated on stack. You don't have to delete it, it will be deleted automatically when comes out of scope.