mocks dont know

Question 1

why use meaningful identifier names

Answer 1

variables make sense
names of subroutine tells the reader what it it
makes code easier to understand
makes code easier to debug and maintain

Question 2

why use subroutines

Answer 2

• each subroutine can be tested separately - making it easier to debug
• many programs can work on a large program once - cutting down development time (splitting it up)
• subroutines can be reused - reducing development time
• code broken down into meaningful subroutines - easier to maintain

Question 3

position

Answer 3

POSITION(word, ‘r’)
word.index(‘r’)
word.find(‘r’)
finds position of a letter

Question 4

substring

Answer 4

slices a string

• SUBSTRING(start, end, str)
  e.g. word = algorithm
  SUBSTRING (3,6,word) = “orit”
• print(word[3:7]) (stops

Question 5

subroutine definition

Answer 5

it is a named out of line block of code that may be executed by writing its name in a program statement

Question 6

comparing linear and binary searches

Answer 6

binary
- in order
- start at middle
- halve set, compare middle item then discard one side, repeat
- suitable for a large no. items
- new items added in the correct place not end

Question 7

computer virus

Answer 7

installed on users computer without their knowledge or permission, to do harm
can copy itself automatically

Question 8

trojan

Answer 8

pretends to be of a helpful use to the user but is really malicious
may spread malware, crash computer, corrupt data, access sensitive info

Question 9

spyware

Answer 9

software that gathers info about a person or an organisation without their knowledge
can collect personal info such as logins

Question 10

firewall

Answer 10

monitors incoming/ outgoing network traffic
decides what to block/allow based on rules
can block certain IP addresses or ports

Question 11

MAC address filtering

Answer 11

determines which devices are allowed to access a network
by whitelisting certain permitted devices (identified by their MAC address)

Question 12

application layer

Answer 12

where network applications operate
data is encoded
- HTTP, HTTPS, FTP, IMAP, SMTP

Question 13

transport layer

Answer 13

sets up communication between two hosts
and establishes settings eg language and packet size
splits data into packets
- TCP and UDP

Question 14

link layer

Answer 14

where network hardware is located eg NIC and OS device drivers
attaches MAC addresses of the sender/ receiver

Question 15

internet layer

Answer 15

addresses packages for transmission
routes packages across the network
attached IP address of sender and destination
- IP

Question 16

layers order

Answer 16

A
T
I
L

Question 17

ethernet protocol

Answer 17

family of related protocols
communicate by sending each other individual data frames
the MAC address specifies the source and destination of each frame

Question 18

wifi protocol

Answer 18

allows electronic devices to connect to a WLAN
the Wireless Access Point receives data from a network
the transmitter converts this into radio waves
which are received by a device

Question 19

TCP

Answer 19

defines how messages are broken into packets and reassembled
detected errors and resends lost packets

Question 20

UDP

Answer 20

connectionless transmission model
can send messages to other hosts on an IP network
like TCP but has no error checking and maintains an open connection - gaming/ streaming

Question 21

IP

Answer 21

identifies the location of the device on a network (the internet) and routes the packets from source to destinations via routers

Question 22

FTP

Answer 22

used to transfer files between a client and server. based on a client server model and uses separate control and data connections between the client and server

Question 23

SMTP

Answer 23

for sending emails between servers over the internet

Question 24

IMAP

Answer 24

receiving email
stores email on server but
allows user to view it on many devices

Question 25

POP

Answer 25

receiving email
downloads new message to local device (no longer on server)

Question 26

character set

Answer 26

a list of the characters and the binary codes used to represent each one
eg ASCII or UNICODE

Question 27

importance of local variables

Answer 27

• keeps subroutine self contained
• subroutines can be used as part of a larger program without variables interfering
• save memory
• program easier to maintain/ debug

Question 28

how are packets used to send data across internet

Answer 28

• website data broken down into packets
• each packet is numbered
• given recipient and sender IP address
• sent separately
• takes most efficient route
• reassembled at destination
• checked for errors
• lost packets resent

Question 29

benefits of layers

Answer 29

each layer is self contained
can be changed individually
layers can have different software/ hardware
network areas can be split between developers