Data Structures and Algorithms in Java[1].pdf - Fulvio Frisone

object (assuming we are allowed access to those
variables).
Variable Modifiers
In some cases, we may not be allowed to directly access some of the instance
variables for an object. For example, an instance variable declared as private in
some class is only accessible by the methods defined inside that class. Such
instance variables are similar to device parameters that cannot be accessed
directly from a remote control. For example, some devices have internal
parameters that can only be read or assigned by a factory technician (and a user is
not allowed to change those parameters without violating the device's warranty).
When we declare an instance variable, we can optionally define such a variable
modifier, follow that by the variable's type and the identifier we are going to use
for that variable. Additionally, we can optionally assign an initial value to the
variable (using the assignment operator ("="). The rules for a variable name are
the same as any other Java identifier. The variable type parameter can be either a
base type, indicating that this variable stores values of this type, or a class name,
indicating that this variable is a reference to an object from this class. Finally, the
optional initial value we might assign to an instance variable must match the
variable's type. For example, we could define a Gnome class, which contains
several definitions of instance variables, shown in in Code Fragment 1.3.
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