Sample Paper Flashcards
A duplicate file finder is an example of a utility. Describe what is meant by a utility
A utility performs a specific task (1) and is usually
related to the upkeep of the system (1).
State what order it will visit each of the files as shown in Fig.1 below
Exhaust ends of each branch then move to the next one.
Explain two characteristics you would look for in a hashing algorithm for this purpose.
Quick to calculate (1 – AO1.2) as lots of files need
to be hashed/needs to be quicker than a bitwise
comparison to make it worthwhile
(1 – AO2.1).
Low chance of collision (i.e. different inputs giving
same output) (1 – AO1.2) to reduce risk of
different files being marked as the same
(1 – AO2.1).
Explain why these apparent duplicates might still be present?
Hashing works on the data/bits (1) and so two
images may appear the same but not be identical
at a bit level (1).
Discuss the two methodologies and justify which you would recommend
The waterfall lifecycle involves linear stages whereas
XP takes on an agile, iterative approach.
The waterfall lifecycle establishes requirements in
early stages and subsequent stages focus on these -
new requirements can be adopted throughout XP.
The waterfall lifecycle focuses on the end user at the
start and then they may be consulted at different
points throughout the project whereas an end user is
integral throughout XP.
The waterfall lifecycle although adopted for large
projects it can be inflexible and limits changing
requirements.
Describe a difference between an array and a linked list.
A linked list is a dynamic data structure (1)
whereas an array is static (1).
Describe one advantage of storing the CSS in an external file rather than it being embedded within HTML files
Content and formatting are kept separate (1).
Changes can be made to the external style sheet
and affect the whole site (1)
saving time (1)
and ensuring consistency (1).
Explain why it is important to check the email address with JavaScript and again when it reaches the server.
The JavaScript check is carried out client-side/in
browser (1) meaning address can be checked and
stopped prior to reaching server (1) reducing
unnecessary load on the server (1).
Describe what is meant by a class
A template (1) defining methods and attributes (1)
used to make objects (1).
Describe what is meant by the term inheritance.
Inheritance is when a class takes on the methods (1) and attributes (1) of a parent class (1).
(ii) Explain one way the game’s developers might use inheritance for Livid Lizards.
The company may wish to use inheritance to
create different types of lizards (1 – AO1.2) using
the lizard class as the base class (1 – AO2.1) and
different types of lizard inheriting from it (1 –
AO2.1).
The game uses a 2D graphics library. Explain why a linker would need to be used after compilation.
The user running the program will not necessarily
have the library installed on their machine (1)
therefore the relevant code needs to be included
within the final executable (1) - it is the job of the
linker to combine this code (1).
(a) Describe a sensor that the device might include to help monitor calories burnt.
Altimeter (1 – AO1.2) when the wearer is
ascending/descending (1 – AO2.1).
(d) Describe why two’s complement may be preferable to sign and magnitude.
It is not easily possible to carry out calculations
using sign and magnitude (1) whereas they will
work with two’s complement (1).
Explain how Linux being open-source would benefit the games company.
This means that a lot of the core functionality they
need is already available (1) so the company just
has to make amendments/additions specific to
their system (1) saving time and money (1).
