2. “What object oriented means”??
• Means we organize s/w as a collection of
discrete objects that incorporate both “data
structure “ and “behaviour”.
• * it shows a contrast to conventional
programming and architectural approaches
such as “procedural approach”,i.e. they
emphasised on “doing” things rather than
“data”.
3. • Objects : an identifiable entity (real or
abstract) with some characterstics and behaviour.
An object is an instance of a class.
Eg. REAL OBJECTS:
3-WHEELER
4-WHEELER
AUTOMOBILE
(class)
5. • Attributes* : features that define charaterstics
of objects.
• *2 objects are distinct even if all their
attribute values are identical.
6. • Operations/funtions:
describe the behaviour of the objects. It is a way to
access the attributes.
Eg: LOVE
• Class :
It is a group of objects that share common properties
and relationships.
Eg : BOYS and GIRLS
BOYS object: PG
GIRLS object: X
Love operation performed on
PG and X gets access to their
attributes “DIL” and “DIMAAG”.
PG X
7. Characterstics of object oriented
architecture
• IDENTIFY : means that data is quantized into
discrete ,distinguishable entities called
objects.Eg. Paragraphs in a document.
• CLASSIFICATION : objects with same data
structure are grouped into a class.
Eg. Classification on Gender basis .
8. • POLYMORPHISM : The ability of a data or a message to
be executed in more than one form is called
polymorphism.
Eg. Case 1:
a and b are objects of class integer.
a = 1 ; b = 2
a + b = 3
Case 2:
a and b are objects of class character.
a + b = ‘ab’ is string.
• In both cases operator is same but result is different.
9. • Real life eg. of polymorphism:
Natural love unnatural love
# operation performed in both the cases is LOVE
but outcome is different.
10. • INHERITANCE:
Capability of one *class of things to inherit
properties from other **class of things.
**Super class
* Sub class
• ABSTRACTION :
The act of representing essential features
without including background details or
explanations .
11. • OBJECT ORIENTED METHODOLOGY-
To employ OOA in ERP we follow an approach called
the OBJECT MODELLING TECHNIQUE (OMT) . It has
following states :
1. Problem Analysis
2. System Design
3. Object Design
4. Implementation
12. • THREE MODELS:
OMT uses three kinds of models to describe a
system.
1. Object model :
Describes the objects in the system and their
relationships.
2. Dynamic model :
Describes the ospects of the system that change
over time, uses STATE diagrams.
3. Functional model :
Describes the data value trasformations within a
system, uses a DFD graph.