Software Development

Question 1

Software Development Methodologies

Answer 1

1) Waterfall
2) Rapid Application Development
3) Spiral
4) Agile
5) Extreme Programming

Question 2

Waterfall

Answer 2

• Linear
• Each phase has a well-defined start and end point
• Cannot move back a phase

Question 3

Rapid Application Development (RAD)

Answer 3

• Produces prototypes until a final version is produced and approved
• Prototypes designed, coded, tested and evaluated with the end user
• May want further improvements

Question 4

Spiral

Answer 4

• Risk-driven - unique risks associated with each project
• Guide for development teams allowing them to adopt elements of other methodologies
• Order depends on the project and its unique risks
• Process model generator where decisions on the software are made based on the risks identified

Question 5

Agile

Answer 5

• Group of methodologies
• Focus on idea that requirements will change during development
• Produces software iteratively
• Refined version of RAD
• Small, iterative software releases with feedback

Question 6

Extreme Programming (XP)

Answer 6

• Aims to produce high-quality code and promote developed quality of life (encourage to adopt practices focusing on simplicity, communication, feedback, courage, respect)
• Agile framework - encourages regular, small, iterative software releases
• Every team member is equal value

Question 7

4 Stages of Compilation

Answer 7

1) Lexical Analysis
2) Syntax Analysis
3) Code Generation
4) Code Optimisation

Question 8

1) Lexical Analysis

Answer 8

• Comments and white space is removed
• Remaining code is turned into a series of tokens
• Symbol table is created to keep track of variables and subroutines

Question 9

2) Syntax Analysis

Answer 9

• Abstract syntax tree is built from tokens produced in the previous stages
• Errors generated if any tokens break the rules of the language

Question 10

3) Code Generation

Answer 10

• Abstract code tree converted to object code
• Object code is the machine code produced before the final step (linker) is run

Question 11

4) Code Optimisation

Answer 11

• Tweaks the code so it will run as quickly and use as little memory as possible

Question 12

Libraries

Answer 12

Ready compiled and tested programs that can be run when needed - typically grouped together into software libraries

Question 13

Benefits of Libraries

Answer 13

• Quick and easy to use in your own code
• Pre-tested so can be sure they are free from errors
• Pre-compiled so typically optimised to run quickly

Question 14

Drawbacks of Libraries

Answer 14

• Adding functionality or making specific tweaks can be difficult
• Sometimes you are ‘black-boxed’ from the actual implementation
• You have to trust the developers