A class level instance variable
is a variable that belongs to a
class but is accessible to all
instances of that class.
It is different from a regular
instance variable, which is specific
to each individual object.
To define a class level instance
variable, you add @@
before the variable name.
Let us take a look at an example.
In this example, we have
a Counter class that keeps track
of the count of objects created.
The @@count class level instance
variable is being used to store and update
the count.
Each time a new instance of the Counter
class is initialized, the @@count
variable is incremented.
The class method count allows us to
retrieve the total count of objects.