Oops abap fundamental

Object-Oriented Programming is a methodology or
paradigm to design a program using classes and
objects. It simplifies the software development and
maintenance by providing some concepts:
1. Class
2. Object
3. Inheritance
4. Polymorphism
5. Abstraction
6. Encapsulation

CLASS
 A class is a user defined data type with attributes,
methods, events, user-defined types, interfaces etc
for a particular entity or business application.

COMPONENTS OF A CLASS
 Attributes: Attributes are variables, constants declared within
a class .
 Methods: Methods are coding blocks which provides some
functionality .
 These methods are similar to Function Modules in ABAP.
 Methods can access all attributes of it`s own class.
 Methods are defined in definition part and implemented in
implementation part.
 We can call methods using CALL METHOD statement.
 Events: Event is a mechanism through which one method of
a class can raise method of other class, without hazard of
instantiating that class.
 Interfaces: Interfaces are similar to classes which contain
methods Without any implementation.
 Interfaces are mainly used to extend the scope or functionality
of the class.

INSTANCE AND STATIC COMPONENTS
 Instance components : These components exist
separately in each instance (object) of the class
and are referred using instance component selector
using ->
 Static components : These components exists
globally for a class and are referred to using static
component selector => .

VISIBILITY OF COMPONENTS OF CLASS
 Public section: Data declared in public section can
be accessed by the class itself, by its subclasses as
well as by other users outside the class.
 Protected section: Data declared in the protected
section can be accessed by the class itself, and
also by its subclasses but not by external users
outside the class.
 Private Section: Data declared in the private
section can be accessed by the class only, but not
by its subclasses and by external users outside the
class.

GLOBAL CLASS AND LOCAL CLASS
 Global Class: Global classes and interfaces are
defined in the Class Builder (Transaction SE24) in
the ABAP Workbench. All of the ABAP programs in
an R/3 System can access the global classes.
 Local Class: Local classes are define in an ABAP
program (Transaction SE38) and can only be used
in the program in which they are defined.

OBJECT
 Objects are nothing but instances of classes, each
object has a unique identity that is memory and it`s
own attributes.
SYNTAX
DATA <instance> TYPE REF TO <class name> .
CREATE OBJECT <instance> .

INHERITANCE
 When one object acquires all the properties and
behaviours of parent object i.e. known as
inheritance. It provides code reusability.
 Inheritance is the concept of passing the behavior
of one class to another class.
 SUPER is the keyword used to represent the super
class in oops, you can access the methods and
attributes the super class using this word super.
 REDIFINATION is the keyword which is used to
overwrite the parent class methods with new
definition.

POLYMORPHISM
 It is a concept by which the same method names
will behave differently in different classes i.e each
method will have its own implementation in different
different classes but with the same name.
 Interface is one of the concept in Object Oriented
ABAP to achieve Polymorphism.

ABSTRACTION
 Hiding internal details and showing
functionality is known as abstraction. For
example: phone call, we don't know the internal
processing.
 In SAP, we use abstract class and interface to
achieve abstraction.

ENCAPSULATION
 Binding (or wrapping) code and data together
into a single unit is known as encapsulation .
 Wrapping up of data into single unit. Or, restriction
on visibility of attributes and methods in the class.
We have 3 levels of visibility:
1. Private
2. Protected
3. Public

Oops abap fundamental

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to Oops abap fundamental (20)

Recently uploaded (20)

Oops abap fundamental