OOP

Question 1

class

Answer 1

template for an object, defining the attributes and behaviours/methods of the objects in the class

Question 2

attributes/instance variables

Answer 2

data associated with a class

Question 3

behaviour/methods

Answer 3

functionality of a class: something that it can do or can be done with it

Question 4

OOP

Answer 4

composed of a number of interacting objects, each of which is responsible for its own data and the operations on that data. Program code creates the objects and allows them to communicate and receive answers. All processing that is carried out in the program is done by the objects

Question 5

information hiding

Answer 5

when a class cannot directly access the attributes of another class when they are declared private

Question 6

why are attributes generally private and classes generally public

Answer 6

so classes can use methods belonging to other classes but cannot directly access or change their attributes

Question 7

constructor

Answer 7

procedure used to create objects in a class

Question 8

instatiation

Answer 8

the creation and naming of a new object in a particular class

Question 9

keyword: new

Answer 9

used when declaring a constructor and instantiate a new object in a class

Question 10

reference (type) variable

Answer 10

named memory location in which you can store information. it holds a pointer or reference to where the object is stored

Question 11

in a variable reference diagram the circle and rectangle refers to..

Answer 11

circles: reference variables
rectangles: primitive data types

Question 12

what are messages used for

Answer 12

to examine or change an object’s state

Question 13

getter messages

Answer 13

written as functions which return an answer

Question 14

setter messages

Answer 14

written as procedures which can change the state of an object

Question 15

objects

Answer 15

instances of a class, which have the same structure methods and attributes but their own data.

Question 16

encapsulation

Answer 16

both the data and methods are stored with an object in a single entity so the behaviour and methods of one object does not affect how another object functins

Question 17

whats so good about encapsulation

Answer 17

programmers can work on different parts without worrying how their code will affect others.
programmers can use methods from other classes without worrying about how they work

Question 18

variable reference diagram

Answer 18

shows in graphical form an object referenced by a reference variable

Question 19

inheritance

Answer 19

when a subclass inherits/shares attributes/methods with its superclass but with their own data and extra methods.

Question 20

what does in inheritance diagram look like

Answer 20

has unfilled arrows pointing up towards superclass

Question 21

polymorphism

Answer 21

refers to a programming language’s ability to process objects differently depending on their class, despite methods having the same name.

Question 22

overriding

Answer 22

defining a method with the same name and formal argument types as an inherited method from a superclass

Question 23

code: defining a class and attributes

Answer 23

class Animal
private name
private position

Question 24

code: defining a procedure

Answer 24

public procedure new ( x, y, z)
aX = x
endprocedure
(new only if constructor)

Question 25

code: an object which is inheriting another objects properties

Answer 25

class mouse inherits Animal
private squeakNoise
public function squeak
...
endfunction

Question 26

how to access private attributes of another object

Answer 26

through functions/procedures: getter/setter

Question 27

if you want to use superclass’ methods, eg called stackSize, how do you do this

Answer 27

super.new(Stacksize)