1.2.4 Types of Programming Language

Question 1

Define and give the benefits of the procedural programming paradigm

Answer 1

Relatively simple to learn for beginners

Applicable to a wide variety of problems.

Uses the programming constructs of sequence, branching, iteration, and recursion.

Uses modular techniques to split large programs into manageable chunks.

Question 2

Define and give the benefits of the object-oriented programming paradigm

Answer 2

Uses features such as classes (methods and attributes), objects, encapsulation, polymorphism and inheritance

Can abstract details of implementation away from the user

Code/classes are reusable & programs are simpler to maintain.

Question 3

Define and give an example of the declarative programming paradigm

Answer 3

Languages such as SQL

Uses statements that describe the problem to be solved, and the language implementation decides the best way of solving it.

Question 4

Define the assembly/low-level programming paradigm

Answer 4

Languages such as Assembly Language

Uses Mnemonics to represent Opcodes

Mainly hardware oriented - Allows greater control of hardware.

Quicker/more efficient to translate.

Makes more efficient use of the CPU.

Question 5

List the 11 mnemonics used in LMC

Answer 5

ADD
SUB

STA
LDA

BRA
BRP
BRZ

INP

OUT

HLT

DAT

Question 6

Write the LMC code to take two inputs and output the biggest of them.

Answer 6

Question 7

State the four addressing modes

Answer 7

Immediate
Direct
Indirect
Indexed

Question 8

Describe the immediate addressing mode

Answer 8

LDA 12 – Loads 12 into the accumulator

The operand is the value to be used

Doesn’t look for the value in RAM as the value is in the instruction.

Question 9

Describe the direct addressing mode

Answer 9

LDA 4 would load the contents of location 4

The operand holds the memory location of the value to be operated on.

Question 10

Describe the indirect addressing mode

Answer 10

LDA 4 would load the address held in location 4 and then load the value in the address that was found using location 4. (Bounces around…)

Operand is the memory location holding a value representing the memory location to be used

Enables a larger range of addressable locations.

Question 11

Describe the indexed addressing mode

Answer 11

Index register = 3 + LDA 4 - Would load the data at location 7

Operand is added to the contents of the ‘Index Register’ to get the memory location of the value needed.

Used to access an array whose elements are in successive memory locations.

Question 12

Describe a class

Answer 12

A template defining methods and attributes, used to make objects.

Question 13

Describe an object

Answer 13

An instance of a class is called an object and is created using a constructor (new)

Question 14

Describe a method

Answer 14

The actions that can be performed by an object; for example, get a position on a game board.

Question 15

Describe an attribute

Answer 15

Each object will have its own public or private attributes.

The attributes of a player in a game of Monopoly might include its PlayerID and money.

Question 16

Define encapsulation and the benefits of using it.

Answer 16

Attributes are set as private so they can only be accessed and changed via public methods

Uses ‘set methods’ to modify the value of a private attribute

Uses ‘get methods’ to retrieve the value of a private attribute

Prevents unexpected changes to attributes having unforeseen consequences.

Question 17

Define inheritance

Answer 17

The child class has its attributes and methods, but it also gets all attributes and methods from the parent class.

Uses the keyword ‘Inherits’

Question 18

Define Polymorphism (overriding)

Answer 18

Code can be written that can handle different objects in the same way, this reduces the amount of code.

Using methods with the same name in a subclass as in a parent class is called overriding, which is a type of polymorphism.

Overriding allows a sub-class to use its method rather than that of the parent.

Question 19

Write a constructor for a Player class with the attributes shown:

PlayerID, boardPosition, money

All objects have a money value of 2000.

Answer 19

public procedure new(thePlayerID, thePosition)
playerID = thePlayerID
boardPosition = thePosition
money = 2000
endprocedure

Question 20

Write the line to instantiate an object called “Boot” at position 10 using the Player class with the attributes PlayerID, boardPosition, money

All objects have an unchangeable money value of 2000.

Answer 20

Boot = new Player(“Boot”, 10)