— Scott McNealy, Sun Microsystems Chairman, President and ceo

214
 
chapter 8
An object contains everything it inherits from each of its 
superclasses. That means every object—regardless of its 
actual class type—is also an instance of class Object.That 
means any object in Java can be treated not just as a Dog, 
Button, or Snowboard, but also as an Object. When you 
say 
new Snowboard()
, you get a single object on the 
heap—a Snowboard object—but that Snowboard wraps 
itself around an inner core representing the Object 
(capital “O”) portion of itself.
Get in touch with your inner Object.
There is only ONE object on the heap here. A Snowboard 
object. But it contains both the Snowboard class parts of 
itself and the Object class parts of itself. 
objects are 
Objects
Object
equals()
getClass()
hashCode()
toString()
Snowboard
equals()
getClass()
hashCode()
toString()
turn()
shred()
getAir()
loseControl()
Snowboard inherits methods 
from superclass Object, and 
adds four more.
to
St
rin
g() hashC
od
e(
)
ge
tA
ir()
turn()
sh
re
d()
eq
ua
ls()
getC
las
s(
)
loseC
on
tro
l(
)
Object
Snowboard
S
n
owboard obj
e
c
t
He treats me like an 
Object. But I can do so 
much more...if only he’d see 
me for what I 
really am.
A single object 
on the heap.

---

interfaces and 
polymorphism
you are here
4
215
Snowboard 
s