Week 1\Lec 1&2

Question 1

how is the problem with the procedure-oriented approach view?

Answer 1

, the problem is viewed as a sequence of tasks to be performed such as reading, calculating and printing

Question 2

what is the program standing on in procedure-oriented approach?

Answer 2

the primary focus is on functions. As a number of functions are written to implement multiple tasks to solve problems

Question 3

What do we mean by global data?

Answer 3

They are variables declared in such away they can be
accessed directly or indirectly (by reference) by all other functions.

Question 4

What is the major limitations of procedural paradigm?

Answer 4

It is difficult to develop a large complex.

Question 5

Why is Procedure‐Oriented Programming unsecure?

Answer 5

every function has complete access to the exposed variables, there is no protection on your data (a new programmer can corrupt the data accidentally when creating function).

Question 6

Why is Procedure‐Oriented Programming not reusable?

Answer 6

Because procedural code needs to recreate the code if is needed to use in another application.

Question 7

Why is procedural code hard to maintain ?

Answer 7

Because if new data is to be added, all the functions using that data need to be modified.

Question 8

What is the fundamental idea behind object‐oriented languages ?

Answer 8

Is to combine into a single unit both data and the functions that operate on that data. and such unit is called object

Question 9

What is oop?

Answer 9

It is a computer programming paradigm that organizes/ models software design around data or objects rather than functions and logic. It does not refer to a specific language but rather to a way to build a program or a methodology to apply.

Question 10

How is the problem viewed in oop?

Answer 10

The problem is divided into the number of entities called objects and then builds data and functions around these objects. Communication of the objects done through function (called method).

Question 11

Why is oop secure ?

Answer 11

Because the data is hidden and cannot be accessed by external functions. It ties the data more closely to the functions that operate on it, and protects it from accidental modification from the outside functions

Question 12

Why is oop reusable?

Answer 12

Because the object is a self contained unit. Therefore, it can be easily incorporated into another program.

Question 13

Why is oop easy to maintain?

Answer 13

Because each object is responsible of its data. When working with OOP languages, you know exactly where to look when something goes wrong

Question 14

What are objects ?

Answer 14

An object is a software bundle of variables and related methods. It have state behavior.

Question 15

what does objects contain from ?

Answer 15

Each object contains data, and code to manipulate the data

Question 16

How does object interact?

Answer 16

When a program is executed, the objects interact by sending messages to one another

Question 17

What can software objects represent?

Answer 17

represent real-world objects, such as a bicycle
represent abstract concepts, such as a counter

Question 18

what is a class?

Answer 18

Software “blueprints” for objects

Question 19

Notes

Answer 19

Remember: a blueprint of a bicycle is not really a bicycle.
When you create an instance of a class, you create an object of that type.
The system allocates memory for the instance variables declared by the class.
You can then invoke the object’s instance methods to make it do something.
It’s possible also to remove the object from the memory.

Question 20

What is encapsulation?

Answer 20

Encapsulation is a process of hiding data members (variables, properties) and member functions (methods) into a single unit”.
And Class is the best example of encapsulation. It’s the first principle of oop!

Question 21

What is the point from encapsulation ?

Answer 21

1.Implementation details of an object can be changed at any time without affecting other parts of the program.
2.Through Encapsulation, Data is not accessible to the outside world, and only those functions which are wrapped in the class can access it.
3.Encapsulation solves the problem at the implementation level.
4. A class can specify how accessible each of its members (variables, properties, and methods) is to code outside of the class.

Question 22

What is absttraction?

Answer 22

it refers to the act of representing essential features without including the background details or explanations.

Question 23

What is data abstraction?

Answer 23

It is a programming(and design) technique that relies onthe separationofinterface andimplementation.

Question 24

What is inheritance?

Answer 24

Themechanismofderivinganew class fromanold classiscalledinheritance or derivation. Theinheritanceisthemostpowerful featuresofOOP.

Question 25

what are the names of new and old calsses

Answer 25

Theold classisknownasbase classwhile new classisknownasderived classorsub class.

Question 26

what does polymorphism mean?

Answer 26

It is a Greek term which means ability to take more than one form.

Question 27

what is polymorphism?

Answer 27

It is a program’s ability to treat objects with the same interface in the same way, without information about the object’s specific type. That mean that Different subclasses of the same superclass, can implement their shared interface in different ways

Question 28

What does binding mean ?

Answer 28

link betweenprocedure call andcode tobeexecute.

Question 29

What is dynamic binding?

Answer 29

Itistheprocess oflinkingofafunctioncall totheactualcodeofthefunctionatrun‐ time.
Thatis,indynamicbinding,theactualcode tobeexecutedisnotknowntothecompiler untilrun‐time.
Itisalsoknownlatebinding.

Question 30

what is message passing ?

Answer 30

Software objects interact and communicate with each other by sending messages to each other.

Question 31

notes

Answer 31

Objectscancommunicate witheachothersby passingmessagesameaspeoplepassingmessage witheachother.
Objectscansendorreceivemessageorinformation.
Conceptofmessagepassingmakesiteasiertotalk aboutbuildingsystemsthatdirectlymodelor simulatetheirreal‐worldcounterparts.

Question 32

Messagepassinginvolvesthefollowingbasicsteps what are they?

Answer 32

1.Creatingclassesthatdefineobjects&theirbehavior.
2.Creatingobjectsfromclassdefinitions.
3.Establishingcommunicationamongobjects.

Question 33

what are the benefits of oop?

Answer 33

User can create new data type or users define data type by making class.
Code can be extended by using inheritance.
Data can be hidden from outside world by using encapsulation.
Object oriented system can be easily upgraded from small system to large system.
It is easy to partition work for same project.
Message passing techniques make communication easier.
Software complexity can be easily managed.
Maintenances cost is less.
Simple to implement.