C.1 System design concepts

Question 1

What are information systems designed as?

Answer 1

Interacting collections of computer programs

Question 2

What do computer programs consist of?

Answer 2

Collections of instructions that tell the computer how to interact with the user and undertake specific functions

Question 3

Define algorithms in the context of computer programs.

Answer 3

Rules used for calculation or problem-solving based on particular representations and structures of data

Question 4

What do data structures enable?

Answer 4

Accurate representation of data relationships and efficient data usage

Question 5

List some examples of data structures.

Answer 5

• Arrays
• Linked lists
• Stacks
• Queues
• Trees
• Graphs
• Tables
• Sets

Question 6

How do arrays organize data?

Answer 6

Store elements of the same type in a specific order and accessed by indexing

Question 7

What characterizes a stack data structure?

Answer 7

Last element in is the first one out (LIFO)

Question 8

Describe the queue data structure.

Answer 8

First-in, first-out (FIFO) rule for processing elements

Question 9

What is the structure of a tree in data structures?

Answer 9

Starts with a root value and branches into sub-trees of children

Question 10

Define graphs in terms of data structures.

Answer 10

Comprise sets of ordered pairs called edges/arcs and entities called nodes/vertices

Question 11

What is the purpose of tables in data structures?

Answer 11

Store elements that can be inserted, searched for, or deleted

Question 12

What is a set in data structures?

Answer 12

Stores certain values without any particular order and no repeated values

Question 13

How does a binary tree improve search efficiency?

Answer 13

Reduces the average search steps compared to linear search

Question 14

What are the average search steps using linear search versus binary search for n items?

Answer 14

• Linear Search: n/2 steps
• Binary Search: log2n steps

Question 15

What are data types?

Answer 15

Data that share a specific property, such as integer, Boolean, alphanumeric characters, or strings

Question 16

What do algorithms manipulate?

Answer 16

The data contained in data structures

Question 17

Define an algorithm.

Answer 17

An explicit, precise, unambiguous, mechanically-executable sequence of elementary instructions

Question 18

What are conditionals in algorithms?

Answer 18

Different steps based on whether a specified Boolean condition evaluates to true or false

Question 19

What is recursion in algorithms?

Answer 19

A solution to a problem depends on solutions to smaller instances of the same problem

Question 20

What is abstraction in problem-solving?

Answer 20

Identifying the underlying abstract problem devoid of unnecessary detail

Question 21

What is the role of programming languages?

Answer 21

Express algorithm(s) and data structure(s) in a particular programming language

Question 22

How do compiled languages work?

Answer 22

Programmer writes general instructions, and a compiler translates these into machine language

Question 23

What is the difference between compiled and interpreted programming languages?

Answer 23

Compiled languages translate code before execution, while interpreted languages translate code during execution

Question 24

What marked the shift from low-level programming to procedural programming?

Answer 24

Higher-level programming languages that allowed writing programs using familiar terms

Question 25

Define the structured programming paradigm.

Answer 25

A subset of procedural programming that deconstructs problems into smaller components

Question 26

What is functional programming focused on?

Answer 26

Modeling the problem rather than the solution using functions that depend only on their inputs

Question 27

What is object-oriented programming?

Answer 27

Models problems in terms of entities (objects) that have attributes and behaviors

Question 28

List the key characteristics of object-oriented programming.

Answer 28

* Class * Abstraction * Encapsulation * Inheritance * Polymorphism

Question 29

What do multi-paradigm languages aim to achieve?

Answer 29

Leverage constructs from different paradigms for specific problems

Question 30

How have modern programming languages evolved?

Answer 30

More abstract from the machine and improved in usability and efficiency

Question 31

What is the primary goal of object-oriented programming?

Answer 31

Facilitates disciplined software development process and enables building secure programs through data-hiding concept ## Footnote Object-oriented programming enhances reusability, extensibility, reliability, and maintainability.

Question 32

Name two examples of object-oriented programming languages.

Answer 32

* Smalltalk * Eiffel ## Footnote These languages exemplify the principles of object-oriented programming.

Question 33

What do multi-paradigm languages aim to achieve?

Answer 33

Leverage constructs from different paradigms to make a program that suits the nature of a specific problem ## Footnote Examples include C++, Leda, Common Lisp, and Scala.

Question 34

How have modern programming languages evolved over time?

Answer 34

More abstract from the machine and closer to human thinking, addressing complex, real-world problems ## Footnote This evolution spans over more than five decades.

Question 35

What are the common components of structured programs?

Answer 35

* Statements to establish the program's start * Declaration of variables * Blocks of code ## Footnote These components create a consistent overall pattern in structured programming.

Question 36

Why are variables declared at the program's start?

Answer 36

The compiler needs to know the type of data stored in it in advance ## Footnote Variables are named to be referred to and typically store values of a given data type.

Question 37

What is Boolean logic?

Answer 37

A two-valued logic allowing only two truth values – ‘true’ and ‘false’ ## Footnote Boolean expressions consist of logical operands and logical operators.

Question 38

What are the basic logical operators in Boolean logic?

Answer 38

* AND * OR * NOT * EQV (logical equivalence) * NEQV (logical non-equivalence) ## Footnote Boolean expressions often involve comparison operators as well.

Question 39

What types of control statements exist in programming?

Answer 39

* Sequential * Decision (conditional) * Iterative ## Footnote These control statements dictate which code sections are executed.

Question 40

What is the purpose of decision (conditional) control statements?

Answer 40

Controls which block of code is executed based on ‘if… then …else’ logic ## Footnote The 'if' block executes when the condition is true, else the 'else' block executes.

Question 41

What are the main categories of iterative control statements?

Answer 41

* FOR loops * WHILE/DO loops ## Footnote These loops control how many times a block of code is executed.

Question 42

What is the structure of a simple FOR loop?

Answer 42

* Initialisation * Condition * Increment or decrement ## Footnote These components define the execution of the loop based on counting.

Question 43

How do WHILE and DO loops differ from FOR loops?

Answer 43

WHILE and DO loops repeat while a condition is true, while FOR loops specify a count ## Footnote The condition is a Boolean expression that determines the loop's execution.