classes and object

1. CLASSES AND
OBJECT
A.Sangeetha M.Sc(info Tech)
Department Of Cs&it
Nadar Saraswathi College Of Arts And Science

2. INTRODECTION:
 Java is a true OO language and therefore the underlying
structure of all Java programs is classes.
 „Anything we wish to represent in Java must be encapsulated in
a class that defines the “state "and “behaviour”of
the basic program components known as objects.
 „C lasses create objects and objects use methods to
communicate between them.

3. CLASS:
A class is a collection of fields (data) and
method (procedure or function) that
operate on that data
child
Centre
radius
Circumference()
Radius()

4. A classes is a collection of
fields(data)and methods (procedure
or function)that operate on that
data.
class Cl a s s N a m e
[extends
Su p e r Cl a s s N a m e ]
{
[fields declaration]
[methods declaration]
}

5. Bare bone class-no fields,no method.
A class with only data fields has no life.
Objects created by such a class cannot
respond to any messages.
public class Circle {
// my circle class
}

6. Methods are declared inside the body of the
class but immediately after the declaration of
data fields.
„The general form of a method declaration is:
type Method
Name(parameter-list)
{
Method-body;

7.  Objects are created dynamically using the