Object Oriented Programming (OOP) - CS304 Power Point Slides Lecture 04

8/13/2019 Object Oriented Programming (OOP) - CS304 Power Point Slides Lecture 04

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Object-OrientedObject-Oriented

Programming (OOP)Programming (OOP)

Lecture No. 4Lecture No. 4


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Recap InheritanceRecap Inheritance

Derived ca!! inherit! a theDerived ca!! inherit! a the

characteri!tic! o" the ba!e ca!!characteri!tic! o" the ba!e ca!!

#e!ide! inherited characteri!tic!$#e!ide! inherited characteri!tic!$

derived ca!! ma% have it! o&n uni'uederived ca!! ma% have it! o&n uni'ue

characteri!tic!characteri!tic!

ajor bene"it o" inheritance i! reu!eajor bene"it o" inheritance i! reu!e


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oncept! Reated &ithoncept! Reated &ith

InheritanceInheritance

*enerai+ation*enerai+ation

,ubt%ping (eten!ion),ubt%ping (eten!ion)

,peciai+ation (re!triction),peciai+ation (re!triction)


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In OO mode!$ !ome ca!!e! ma% haveIn OO mode!$ !ome ca!!e! ma% have

common characteri!tic!common characteri!tic!

e etract the!e "eature! into a ne&e etract the!e "eature! into a ne&

ca!! and inherit origina ca!!e! "romca!! and inherit origina ca!!e! "rom

thi! ne& ca!!thi! ne& ca!!

/hi! concept i! 0no&n a!/hi! concept i! 0no&n a!



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1ampe *enerai+ation1ampe *enerai+ation

Circle

colorvertices

radius

move

setColor

computeArea

Linecolor

vertices

lengthmove

setColor

getLength

Triangle

color

vertices

anglemove

setColor

computeArea


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Shapecolor

vertices

move

setColor

Circleradius

computeArea

Linelength

getLength

Triangleangle

computeArea


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Teachername

age

gender

designation

salaryteach

takeExameat

walk

Studentname

age

gender

program

studyYearstudy

heldExam

eat

walk

Doctor

nameage

gender

designation

salarycheckp

prescri!e

eat

walk


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Personnameage

gendereat

walk

Teacherdesignation

salary

teach

takeExam

Studentprogram

studyYear

study

heldExam

Doctordesignation

salary

checkp

prescri!e


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,ub-t%ping 2 ,peciai+ation,ub-t%ping 2 ,peciai+ation

e &ant to add a ne& ca!! to ane &ant to add a ne& ca!! to anei!ting modeei!ting mode

3ind an ei!ting ca!! that aread%3ind an ei!ting ca!! that aread%impement! !ome o" the de!ired !tateimpement! !ome o" the de!ired !tateand behaviourand behaviour

Inherit the ne& ca!! "rom thi! ca!!Inherit the ne& ca!! "rom thi! ca!!and add uni'ue behaviour to the ne&and add uni'ue behaviour to the ne&

ca!!ca!!


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,ub-t%ping (1ten!ion),ub-t%ping (1ten!ion)

,ub-t%ping mean! that derived ca!! i!,ub-t%ping mean! that derived ca!! i!

behavioura% compatibe &ith thebehavioura% compatibe &ith the

ba!e ca!!ba!e ca!!

#ehavioura% compatibe mean! that#ehavioura% compatibe mean! that

ba!e ca!! can be repaced b% theba!e ca!! can be repaced b% the

derived ca!!derived ca!!


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1ampe 1ampe

,ub-t%ping,ub-t%ping

(1ten!ion)(1ten!ion)

Personname

agegender

eats

walks

Student

programstudyYear

study

takeExam


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1ampe 1ampe

,ub-t%ping,ub-t%ping

(1ten!ion)(1ten!ion)

Shapecolor

vertices

setColor

move

Circleradius

computeC"

computeArea


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,peciai+ation (Re!triction),peciai+ation (Re!triction)

,peciai+ation mean! that derived,peciai+ation mean! that derived

ca!! i! behavioura% incompatibeca!! i! behavioura% incompatibe

&ith the ba!e ca!!&ith the ba!e ca!!

#ehavioura% incompatibe mean! that#ehavioura% incompatibe mean! that

ba!e ca!! cant a&a%! be repaced b%ba!e ca!! cant a&a%! be repaced b%

the derived ca!!the derived ca!!


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1ampe ,peciai+ation1ampe ,peciai+ation

(Re!triction)(Re!triction)

Personage # $%&&'%%(

)

Adultage # $'*&&'%%(

)

setAge+ a ,

)

setAge+ a ,

)

age - a

./ age 0 '* then error

else

age - a


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1ampe ,peciai+ation1ampe ,peciai+ation

(Re!triction)(Re!triction)

IntegerSet)

1aturalSet)

add+ elem ,

)

add+ elem ,

)

add element

to the set

./ elem 0 ' then

errorelse

add element

to the set


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OverridingOverriding

5 ca!! ma% need to override the5 ca!! ma% need to override thede"aut behaviour provided b% it! ba!ede"aut behaviour provided b% it! ba!e

ca!!ca!!

Rea!on! "or overridingRea!on! "or overriding

Provide behaviour !peci"ic to a derivedProvide behaviour !peci"ic to a derivedca!!ca!!

1tend the de"aut behaviour1tend the de"aut behaviour

Re!trict the de"aut behaviourRe!trict the de"aut behaviour

Im rove er"ormanceImprove per"ormance


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1ampe ,peci"ic #ehaviour1ampe ,peci"ic #ehaviour

Shapecolor

vertices

draw

movesetColor

Circleradius

draw

computeArea

Linelength

draw

Triangle

angle

draw

computeArea


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1ampe 1ten!ion1ampe 1ten!ion

2indowwidth

height

open

closedraw

Dialog3oxcontrols

ena!le

draw

'4 .nvoke 2indow5s

draw

64 draw the dialog

!ox


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1ampe Re!triction1ampe Re!triction

IntegerSet)

1aturalSet)

add+ elem ,

)

add+ elem ,

)

Add element

to the set

./ elem 0 ' then

give errorelse

Add element

to the set


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1ampe Improve Per"ormance1ampe Improve Per"ormance

a!! ircea!! irce

override!override! rotaterotate

operation o" ca!!operation o" ca!!,hape &ith a Nu,hape &ith a Nu

operation.operation.

Shapecolor

coord

draw

rotatesetColor

Circleradius

draw

rotate


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5b!tract a!!e!5b!tract a!!e!

5n ab!tract ca!! impement! an5n ab!tract ca!! impement! an

ab!tract conceptab!tract concept

ain purpo!e i! to be inherited b%ain purpo!e i! to be inherited b%

other ca!!e!other ca!!e!

ant be in!tantiatedant be in!tantiatedPromote! reu!ePromote! reu!e


22/26

1ampe 5b!tract a!!e!1ampe 5b!tract a!!e!

TeacherDoctorStudent

6ere$ Per!on i! an ab!tract ca!!6ere$ Per!on i! an ab!tract ca!!

Personname

age

gender

eat

walk


23/26

1ampe 5b!tract a!!e!1ampe 5b!tract a!!e!

3usTruckCar

6ere$ 7ehice i! an ab!tract ca!!6ere$ 7ehice i! an ab!tract ca!!

Vehiclecolor

model

accelerateapply3rakes


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oncrete a!!e!oncrete a!!e!

5 concrete ca!! impement! a5 concrete ca!! impement! a

concrete conceptconcrete concept

ain purpo!e i! to be in!tantiatedain purpo!e i! to be in!tantiated

Provide! impementation detai!Provide! impementation detai!!peci"ic to the domain contet!peci"ic to the domain contet


25/26

1ampe oncrete a!!e!1ampe oncrete a!!e!

6ere$ ,tudent$ /eacher and Doctor6ere$ ,tudent$ /eacher and Doctor

are concrete ca!!e!are concrete ca!!e!

TeacherDoctorStudent

program

studyYear

study

heldExam

7erson


26/26

1ampe oncrete a!!e!1ampe oncrete a!!e!

8 9ere: Car: 3us and Truck are concrete

classes

3usCar

Vehicle

Truckcapacity

load

unload

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Object Oriented Programming (OOP) - CS304 Power Point Slides Lecture 04