1. When you created an array and want to return the memory to system. You need to explicitly add [] to show that that's an array you want to return, so more than one destructors will be called.
2. However, things might not be that simple. Imagine you are fixing a bug and trying to delete an object someone else wrote, for example
std::string *foo = new Foo;
How will you delete it? Pretty much everyone would write
detele foo;
But that is not necessary right until you look a little bit further and come across this line:
typedef std::string Foo[];
Oops, Foo is actually an array of string, so you gonna need to write
delete foo[];
So, what lesson have you learned from here?
One is that don't typedef array. And the other is to use STL library instead of dynamic allocated memory unless it's absolutly necessary.