Answer 1

Constructors are automatically called when you create an object. You don't need to use it manually or can't access by object. It's used to create an object.

Answer 2

We don't "use" the constructor, the `new` operator does, during the instantiation of an object of the class, to setup the new instance.

Didn't get what you mean by "to access it using object". Constructor is a special method that doesn't return anything, not even callable.

Answer 3

In C++ a structure can have constructor & destructor just like a class.