1
Q
What is the software development process?
A
Analysis
Design
Implementation
Testing
Documentation
Evaluate
2
Q
What do you do for the design stage?
A
The team plans how the system will work. They design the layout with a collection of wireframes to show progressions, data flow, and decide what tools or languages to use.
3
Q
What is a variable?
A
Holds one piece of data of one data type. In RAM
4
Q
What are the different data types?
A
Character - one letter number or symbol
String - a collection of characters
Integer - Whole number
Real / Float - Decimal number
Boolean - True or False
5
Q
What are the 2 things under basic program structure?
A
Block comment
Line comment
6
Q
When naming a variable what should you do?
A
Give it a sensible name
No spaces
7
Q
What are the 5 factors of readability?
A
Sensible variable and list name
White space
Colour coding text
Use indentation for linked code
Use internal commentry
8
Q
What is selection?
A
Selection is refering to additional statements. To carry out an action: Conditional statements
9
Q
What are conditional statements?
A
They carry out an action if or while a condition is met: If…elif…else, while…
10
Q
What are comparison operators?
A
> < == =!
11
Q
What are the logical operators?
A
And, or, not
12
Q
What is iteration?
A
Loops
13
Q
Why do we use iteration?
A
Saves repeating code
Saves memory
Improves efficiency
Improves readability
Reduces risks of syntax errors
14
Q
What is an array?
A
A memory location that stores multiple data items of one data type.
Arrays are known as lists
Arrays are declared using [ ]
Lists starting number is 0
Stored in RAM
They are 1 dimensional
15
Q
What are some standard algorithms?
A
Input validation
Linear search
Count occurences
Min
Max
16
Q
How to evaluate a program?
A
Fitness of purpose - does it reach the requirements
Efficiency of code - loop, lists, pre - defined functions and procedures
Robustness - ability to manage errors
Readability - you should know these
17
Q
What is the software development process called?
A
Waterfall method
Iteration method
18
Q
In the waterfall method what happens in the analysis stage?
A
This is where the project team finds out what the customer wants the system or software to do. All needs and goals are written down clearly.
19
Q
In the waterfall method what happens in the implementation stage?
A
The actual building stage. Programmers write the code according to the design.
20
Q
In the waterfall method what happens in the testing stage?
A
The system is checked to make sure it works correctly. Any errors or bugs found are fixed.
21
Q
In the waterfall method what happens in the documentation stage?
A
The finished system is installed and delivered to the user or customer.
22
Q
In the waterfall method what happens in the evaluation stage?
A
After the system is in use, updates and small fixes are done to keep it working properly.
23
Q
What is a structure diagram used for?
A
To design a program by taking the goal and splitting it into sub-steps. The sub-steps can then be broken below the sub-step to give more detail.
24
Q
What is pseudocode?
A
A text based design methodology that is made up of English like phrases.
25
What is a record?
Records hold multiple data of multiple data types - databases.
26
What are the database data types?
Short text
Long text
Integer
Boolean
Float / Real / Decimal
URL - website
OLE - image
27
What are the 3 operators?
Logical
Comparison
Arithmetic
28
What are the arithmetic operators?
+ - / * % (modulas (remainder))
29
What is the mantissa and exponent?
0.345x10*15
Mantissa - 345
Exponent - 15
30
What are the computational constructs?
Sequence (line by line)
Iteration (loops)
Selection (if...elif...else, while)
31
What are the 3 types of loops under iteration?
Fixed - changeable number of times
Conditional - while a condition is or isn't met
Pre - defined - function produce a result, procedures carry out an action.
32
What is an algorithm?
A set of instructions
33
What are the 3 types of test data?
Normal, extreme and exceptional / error
34
What is normal data for testing?
Normal data is within the boundries e.g. percentage - 1 - 99
35
What is extreme data for testing?
The actual boundries for the data e.g. percentage - 0 - 100
36
What is exceptional / error data for testing?
It's outside the boundries or a different data type e.g. percentage - >100 or <0, string instead or integer.
37
What are the errors?
Syntax, executional and logical
38
What is a syntax error?
Miss spelling, too many or too little punctuation marks
39
What is a executional error?
It's were it's impossible e.g. / 0
40
What is a logical error?
The code works but not in the right way
41
What are some ways to make efficient use of programming?
Repition - use for index in range
Arrays - instead of variables
Selection statement - such as elif
Logical operators - and, or, but
42
What are some ways to sort the robustness of the program?
When the error is found tell the user
Give the user another opportunity for input
43
What is the base of denary digits and binary?
Denary digits - 10
Binary - 2
44
What is a pixel?
An individual square in a bitmap image. Coded to represent a colour.
45
What are these:
1bit
8 bits
1024 bytes
1024 KB
1024 MB
1024 GB
0 or 1 = black or white
1 byte
1 KB
1 MB
1 GB
1 TB
46
What is standard ASCII?
American Standard Code for Information Interchange
Has a povity or error check bit
Has 128 options [0 - 127] for letters / numbers and symbols
47
What is extended ASCII?
American Standard Code for Information Interchange
Has 256 options [0 - 255] for letters / numbers and symbols
48
What is UNICODE?
The step up from extended ASCII and uses 16 bits (65,500 characters) to represent symbols from all major languages.
49
What does JPEG stand for?
Joint Photographic Expert Group
50
What does PNG stand for?
Portable Network Group
51
What are the 2 graphic types?
Bitmap and Vector
52
What does vector fit?
JPEG, JPG, PNG and animation GIF
53
What does bitmap fit?
BMP and transparent GIF, PNG
54
What are the advantages of bitmap?
- Can represent real - life images such as photos
- Can edit images at pixel level
- Lots of standard file formats for exchanging data between applications and users
55
What are the disadvantages of bitmap?
- Large file size - even an empty bitmap will still need the same number of bits per pixel
- Resizing will result in pixelation
- Bitmap software cannot change object attributes once drawn
56
What are the advantages of vector?
- Attributes can be changed easily
- Objects can be layered
- Objects can be linked or connected to each other
- Resizing does not result in pixelation - you are just changing attributes
- Small file size - you only store the data for objects you create
57
What are the disadvantages of vector?
Cannot represent photographic data
58
What is vector?
- Image where code is a series of instructions that describe the objects.
- Images created by combining objects with attributes, other aspects on canvas are un-coded.
- Vectors are able to take objects apart and layer them.
- Vectors are able to set size to % of canvas so it changes with the image.
- File size is defined by the number of objects and their attributes.
- Vectors have scalable graphics (increase size without pixelation)
59
What are the 4 types of objects?
Rectangles, Elipses, Polygons and lines
60
What are some attributes of objects?
X and Y coordinates
line colour
line thickness
Fill colour
Radius
Relative size
61
What is bitmap?
- store image in pixel dividing the 2D array of pixels, then storing a binary value to represent each pixel
- Not scalable because lose resolution
- Has 24 bits (16.7 million colours)
- When adding or removing data the file size doesn't change.
62
What is the resolution?
The amount of pixels in a bitmap image.
63
What is bit depth?
The options for the colour of bits.
64
What is true colour?
The level at which your eyes can't tell the difference between adjacent colour values.
64
How to work out the resolution?
pixels x bit depth
65
What is the structure of a computer?
Input devices -> Processor -> Output devices
Processor -> ROM
Processor -><- RAM
(Processor + ROM + RAM) -><- Storage devices
66
What are some input devices?
Keyboard, Microphone, Touch-pad
67
What are some output devices?
Screen, Monitor, Motor, LED's
68
What are some storage devices?
CD's, USB's, Hard Drives
69
What is ROM?
Read only memory - basic instructions
70
What is RAM?
Random access memory - holds more complex programs
71
What do input devices do?
Convert real world information to binary data
72
What does the processor do?
Changes the data by following an algorithm
73
What do output devices do?
Converts the binary data back into real world information
74
What is the processor made up of?
ALU - arithmetic and logic unit
Control unit
Registers
75
What is the ALU for?
To perform any kind of mathematical or logical work
76
What is the control unit for?
Coordinating all the activities happening in the computer that require some of the processors time. Such as: Fetching instructions, decoding instructions, executing instructions, respond to peripherals, managed by the clock signal.
77
What are peripherals?
Input and output devices
78
What are the registers for?
Temporary storage locations based on the processor chip.
79
What are the 3 registers?
Program counter
Address register
Data register
80
What is the ROM and RAM for?
Storage / memory. Each location can store instructions or data and is referred to by a binary number called an address. Unique.
81
What does FAT stand for?
File Allocation Table
82
What is the processor also called?
CPU - Central Processor Unit
83
What is the difference between the program counter and the address registers?
Program counter - Stores the address of the next instruction to be executed.
Address - Stores the address in memory the CPU wants to access. Used when reading or writing data in RAM.
84
What are buses?
Electrical wires that run from CPU to memory modules. Each one is 1 binary digit.
85
What are the 3 buses?
Address
Data
Control
86
What does the address bus do?
Takes the address that needs to be accessed from CPU to memory module one direction.
87
What does the data bus do?
Takes the data either way.
88
What does the control bus do?
Tells the computer whether to read the data from memory or to write the data from CPU to memory.
89
What is the level of language that computers understand?
Low level
90
What is the main low level language?
Machine code which is binary and connects directly to the electricity.
91
What are some features of high level languages?
- They use English like commands to represent groups of operations.
- They use human style mathematical and logic systems rather than binary.
- They simplify reading and writing data to and from memory by using variables instead of addresses.
92
What is the purpose of these high level languages:
SQL
Python
Scratch
For databases
As generic code
To be an easy drag and drop (object oriented)
93
Whats between normal and high level languages? Give example.
Design languages
Psuedocode
94
What are the 2 types of translators?
Interpreter - line by line
Compiler - all done at once
95
What are the advantages of an interpreter?
- It is easier to debug programs as errors are found when they are executed.
- It is quicker to debug as you can keep running a program from the last successful line of code.
96
What are the disadvantages of an interpreter?
- Can be slow to run the code as the processor needs to run the translator software and the interpreter code.
- You will always need the interpreter to run the code which may not be good for software you wish to distribute.
- Anyone can see (and copy) your source code.
97
What are the advantages of a compiler?
- A program will run without needing to be translated any more which is good for distributing software.
- A program will run much more quickly as the processor is not needing to translate the code any more.
- Compiled code is difficult to reverse - engineer so your competitors cannot just copy your source code.
98
What are the disadvantages of a compiler?
- Debugging can be complex as errors are not reported immediately.
- You will need to re-compile your code every time an error is found and corrected. This may take time with a long program.
99
When should you use an interpreter?
When developing and alpha testing the program.
100
When should you use a compiler?
When you are ready to move on to beta testing or when handing over to the client.
101
What are the different settings on a monitor / screen that will decrease enviromental impact?
Brightness
Standby
Hibernate
Turn off
102
What is the advantage to sleep mode?
You can restart quickly because RAM continues to be powered.
103
How does hibernating a computer work?
It takes longer to resume than sleep mode but uses less electricity. It involves copying the RAM onto the backing storage then powering down the system.
104
What to do to maximise battery life on a computer?
Alter the speed of the processor or the number of cores being used and turn off network adaptors like wi-fi and Bluetooth.
105
Do you change devices or upgrade them for better enviromental impact?
Upgrade them
106
What is hacking?
The unauthorised access to a computer.
107
What are the levels of hacking?
Level 1 - Looking around
Level 2 - Going on and doing something
Level 3 - Doing something that severely affects the computer or the person
108
What are Viruses?
Any piece of code that affects the browser or programs.
109
What are Trojans?
A piece of software that pretends to be safe in order to trick the user into installing it.
110
What are Worms?
Software that can spread by itself without needing a user to install or run it.
111
What are Viruses, Worms and Trojans?
Malicious software or code
112
How do firewalls work?
By examining data that is sent or received by your device. Firewalls can be configured with rules by their users that will determine how they respond to received (and sent) packets of data. Firewalls can block or allow access to certain websites / IP addresses called whilelisting. Firewalls don't detect things.
113
What is a packet of data?
Computers break down your data into small sections called packets.
114
what is encryption?
A technique used to scramble data into an unreadable form. Without knowing the settings or key used to scramble the data it's nearly impossible to reverse. You can either have symmetric or asymmetric encryption.
115
What is the difference between symmetric and asymmetric encryption?
Asymmetric is were each person has a different password.
Symmetric is were each person has the same password.
116
Why should the program have readablity?
- To be able to find and fix errors
- To share code with others
- To make programming less stressful
117
What are the different types of users?
Novice
Intermediate
Expert
118
What is a database?
A means to store and organise information as discrete data items. It's essentially a computer.
119
How is a database organised?
Into tables that contain fields of data. A table being an entity and all records about everything. Groups of linked tables being an entity set. A field is an attribute and essentially a variable. Records are a set of fields about something.
120
What is a single table called?
A Flat File database
121
What is a multiple linked table called?
A relational database
122
What are the issues with flat file databases and what is the solution to these?
Inconsistency - Same data spelt differently, difficult to search and find results.
Redundancy - Repeated data that wastes storage space.
Solution - Create a relational database using unique identifiers / keys.
123
What is the primary key?
An attribute / field that uniquely identifies each record.
124
What is the foreign key?
A primary key that appears in a lined table.
125
How to draw an entity occurrence diagram?
State all the data, group the data according to characteristics, draw lines between related data.
126
How to design a database?
- Entity occurrence diagram
- Entity relationship diagram
- Data dictionary
- JQL Query design
127
How to plan an entity relationship diagram?
Identify the entities - Draw a rectangle for each name
Draw the relationship
State the nature of the relationship
Add attributes
Identify primary key and foreign key - Primary = underline and foreign = asterix
128
How to plan the data dictionary?
Detailed info about each entity and attribute
129
What are the 4 types of data validation?
Restricted choice - limited to set group of options
Presence check - must have a value
Character length - must be a certain number of characters
Range check - must be within a range of values
130
How does the JQL query design work?
Its how you search for specific data in one or more tables.
- Input which fields show on screen
- Input which tables come to the query
- Input what is the search criteria
- Input how the info should be sorted
EVERYTHING
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Decks in class (13)
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