Types Of Programming Language

Question 1

What is procedural programming?

Answer 1

• Form of imperative programming. Tell computer how to solve problem
• Tell the computer steps we want the computer to go through to solve a problem

Question 2

What does it mean if a programming language is Turing complete?

Answer 2

-Can solve all the problems it has been proved computers can solve

Question 3

What is a low level language?

Answer 3

• Each line represents a single machine code instruction
• Much longer than HLL code
• Examples include assembly language which uses mnemonics to represent binary instructions
• Each type of processor has its own instruction sets available
• Code is not portable

Question 4

What are the 11 instructions in LMC?

Answer 4

ADD
SUB
LDA
BRA
BRP
BRZ
INP
OUT
HLT (end program)
DAT (data location)
STA (store)

Question 5

What is a disadvantage of procedural programming?

Answer 5

-code is re-used a lot and some is redundant

Question 6

What is a class in OOP?

Answer 6

• logical grouping of data and functions
• logical connection between the contents of the class
• based on objects in the real world or concepts like HTTPReequest
• blueprints for creating objects. A manual for constructing a certain object, telling it what attributes and methods it should have
• one class can create many objects
• can be re-used in other programs

Question 7

What is OOP inheritance?

Answer 7

• a child class derives the data and behaviour of a parent class
• if we want to change the base data or behaviour we only have to change it in the parent class and propagate to the child classes
• allows us to create a child class that has all the methods and attributes of its parent as well as attributes and methods of its own
• the children are a “type of” the parents main class

Question 8

Example of inheritance in OOP?

Answer 8

• car making factory with a parent class of “vehicle” that states that the vehicles will have wheels and engines
• sub classes will be “car” or “motorbike” and they will tell you how many wheels you need and what size of engine

Question 9

What is what is overriding in OOP?

Answer 9

When a method in a child class is used to replace a method inherited from the parent class

Question 10

What is polymorphism?

Answer 10

• methods behave differently according to the context in which they are used
• eg; when we have a polymorphic array that contains objects of different classes but that inherits from the same parent class. So voicecontrol() does the same thing on all smartphones but is implemented differently on all of them

Question 11

What is encapsulation?

Answer 11

• the mechanism by which we can restrict access to some of the components that comprise an object
• the objects internal representation cannot be seen from outside its definition
• the pattern of making attributes in a class private but allowing them to be changed and accessed through public methods

Question 12

How do we access encapsulated data?

Answer 12

• use getters, get(), and setters, set()
• getters allow other classes to see the value of an attribute
• setters allows the attribute value to be changed
• private means the method or attribute is only accessible from within that class. Other classes cannot access them

Question 13

What is encapsulation used for?

Answer 13

• we can ensure that the internal data cannot be accidentally set to an inconsistent or invalid stat
• isn’t there to stop malicious attempts to change attributes
• there to reduce the chance of mistakes occurring through attributes being altered in an unforeseen way by other objects

Question 14

What are the four methods of accessing memory locations in assembly code?

Answer 14

Direct, immediate, indirect and indexed addressing

Question 15

What is direct addressing?

Answer 15

• The operand represents the memory location of the data we want.
• STA 6 will store the contents of location 6 in the accumulator

Question 16

What is Immediate addressing?

Answer 16

• the operand is the actual value we want

- STA 6 means store 6 in the accumulator

Question 17

What is indirect addressing?

Answer 17

• the operand is the address of the data we want
• useful as we have a limited number of bits we can use for the operand (opcode takes up a few)
• we use all the bits in the memory location for an address, so we can access a much wider range of memory locations
• eg: location 6 contains 85 and location 85 contains 21. STA 6 will load 21 into the accumulator

Question 18

What is indexed addressing?

Answer 18

• one of the registers in the CPU is the index register
• the value given is the base address. This is then added to the value in the index register to give the memory location. The value from this memory address is loaded into the accumulator
• by incrementing the index register it is possible to iterate effectively through an array

Question 19

What are properties and what are methods in OOP?

Answer 19

Eg; Phone is the object
Properties = make, model, colour (description)
Methods = sends/receives calls, check voicemail (what it does)

Question 20

What is a benefit of OOP over procedural languages?

Answer 20

-allows more complex functionality but with less code