When an object of a class is created, the class is said to be instantiated. All the instances share the attributes and behavior of the class. But the values of those attributes; i.e., the state is unique for each object.
A single class may have any number of instances.
As we declare variables like (type name;), this notifies the compiler that we will use name to refer to data whose type is type.
|
|
With a primitive variable, this declaration also reserves the proper amount of memory for the variable. So for reference variable, type must be strictly a concrete class name. In general, we can’t create objects of an abstract class or an interface.
Dog tuffy;If we declare reference variable (
tuffy) like this, its value will be undetermined (null) until an object is actually created and assigned to it.
Simply declaring a reference variable does not create an object.