Software Design & Development: Unit 1 - Programming Paradigms

Question 1

What is a programming paradigm?

Answer 1

It is a specific style of programming (i.e. Imperative, Concurrent and Object Oriented)

Question 2

What is Imperative Programming?

Answer 2

A type of language used to create programs consisting of a set of commands

Question 3

What are the 3 basic control structures of Imperative Programming?

Answer 3

• Sequence
• Selection
• Iteration

Question 4

What is the ‘sequence’ control structure in Imperative Programming?

Answer 4

When one command is executed followed by another in Imperative Programming

Question 5

What is the ‘selection’ control structure in Imperative Programming?

Answer 5

If a condition is true then one command is executed, else if that condition is false then a different command is executed

Question 6

What is the ‘iteration’ control structure in Imperative Programming?

Answer 6

A command is executed a set number of times

Question 7

What are variables in Imperative Programming? (2)

Answer 7

• They are used to store values in a program, which can be changed.
• They are passed as parameters to procedures and functions

Question 8

What is ‘modularity’ in Imperative Programming?

Answer 8

When commands are combines into a single block of self-contained code that can be used within a program to change values of parameters passed into them

Question 9

What are the advantages of ‘modularity’ in Imperative Programming? (3)

Answer 9

• Modules can be treated as separate sub-programs which can be tested independently of the main program
• Large programming projects will benefit from a modular approach because several different people can work on different modules simultaneously
• Code will be more readable because the main part of a program can be presented as a concise set of commands, that call a procedure or function

Question 10

What is Object-Oriented Programming?

Answer 10

A style of programming allowing a program to be separated into blocks of related data, and the operations which apply to that data.

Question 11

What is an ‘object’ in OO programming?

Answer 11

A block of related data and the operations which apply to that data, where the data can only be accessed directly by its associated operations.

Question 12

What is a ‘class’ in OO programming?

Answer 12

A class is a blueprint for an object, and when it is defined any number of objects can be created from that class.

Question 13

What must be included in a ‘class definition’ in OO programming?(2)

Answer 13

• Instance Variables (or properties), which is what data the class needs to use
• Methods, which is what the class will be able to do with data

Question 14

What is a ‘class library’ in OO programming?

Answer 14

A set of classes that can be used by developers as common building blocks for complex applications

Question 15

Explain superclasses and subclasses in OO programming

Answer 15

The superclass establishes a common interface and foundation, which subclasses can inherit, modify, and append

Question 16

What is ‘inheritance’ in OO programming?

Answer 16

This is where a subclass is created which inherits the instance variables and methods of the class above it, but can have additional instance variables and methods of its own

Question 17

What is an advantage of using ‘inheritance’ in OO programming?

Answer 17

There is no need to repeat lines of code to define instance variables or methods, as subclasses will simply inherit these from their superclass

Question 18

What is an actual parameter? What is a formal parameter?

Answer 18

• Actual parameters are parameters as they appear in function calls
• Formal parameters are parameters as they appear in function declarations

Question 19

What is ‘encapsulation’ in OO programming? (2)

Answer 19

• This is where an objects properties would be hidden and inaccessible outside the a class or subclass.
• Code within the methods of the class can manipulate the properties of that class

Question 20

What is Concurrent Programming?

Answer 20

A style of programming where several streams of operations may execute simultaneously, and can also communicate and interfere with one another

Question 21

What are 3 potential problems that can occur in Concurrent Programming?

Answer 21

• Deadlock
• Race Condition
• Resource Starvation

Question 22

What is ‘Deadlock’ in Concurrent Programming?

Answer 22

This is when two threads are waiting for the other to finish and as a result neither does.

Question 23

What is ‘Race Condition’ in Concurrent Programming?

Answer 23

This is when two threads are potentially racing against each other to update or access a variable

Question 24

What is ‘Resource Starvation’ in Concurrent Programming?

Answer 24

This is where the priority given to one or more threads means that they continuously access resources which are needed for another thread.

Question 25

What are the advantages of Concurrent programming? (2)

Answer 25

• Complex programs can make better use of multiple resources in new multi-core processor architectures
• A user can interact with applications while tasks are running (i.e. stop downloading in web browser)