Topic 4

Question 1

List two criteria to use when assessing whether a solution is satisfactory.

Answer 1

1. Speed

2. Readability

Question 2

What are sub-procedures?

Answer 2

Sub-procedures are procedures that have no use on their own but are used in other procedures to contribute to solving a larger problem, which are known as methods in Java.

Question 3

List 3 benefits of modular programming.

Answer 3

1. Reusability
2. Debugging
3. Organisation (split up workload)

Question 4

List two examples of decision making statements.

Answer 4

1. if (else)

2. switch

Question 5

Every decision making statement returns a…

Answer 5

boolean

Question 6

What are the 3 parts of a solution?

Answer 6

1. Input
2. Processes/procedures
3. Output

Question 7

Why is pre-planning important?

Answer 7

E.g.

we need somewhere to store information about what to code, inputs, outputs etc.

Question 8

What are the two tasks in a software development cycle that must be conducted concurrently?

Answer 8

Testing and development

Question 9

What are gantt charts used for?

Answer 9

Managing the period of time in which a task will be in development

Question 10

What are pre-conditions? E.g.?

Answer 10

Pre-conditions are things that need to be tested before executing a solution. It is necessary for some solutions because the functions of a solution may have to rely on these pre-conditions, e.g. connecting to a database requires internet connection

Question 11

What are post-conditions? E.g.?

Answer 11

Post-conditions are things that must be tested in order to check that the solution has done what it’s supposed to have done, e.g. printing out the results and checking if it is reasonable.

Question 12

When are exceptions thrown?

Answer 12

An exception occurs when the program expects something but the input does not match as expected.

Question 13

List 3 advantages of implementing parts concurrently.

Answer 13

1. Efficiency/time
2. Organisation in a large group
3. Some parts may depend on other parts

Question 14

What is concurrent processing?

Answer 14

Essentially multitasking, a real life example of this is the building of a car, where the different parts are pre-built separately but concurrently.

Question 15

What is a major strength of concurrent processing?

Answer 15

Speed

Question 16

List two weaknesses of concurrent processing.

Answer 16

1. Cannot be used when processes of constructing a solution must be linear (i.e. one function depends on the output of another)
2. Difficult to code, debug and trace

Question 17

What is an abstraction?

Answer 17

Abstraction in a solution to a problem in the design level, showing a concept of an object rather than the actual object.

Abstraction is used for hiding the unwanted data and giving relevant data and focuses on what the object does rather than how it does it.

Question 18

What is the structure of a while loop in pseudocode?

Answer 18

loop while CONDITIONS
actions
end loop

Question 19

What is the structure of a do while loop in pseudocode?

Answer 19

loop until CONDITIONS
actions
end loop

Question 20

What are the two most common ways of using linear arrays?

Answer 20

Sorting and searching

Question 21

List two types of sorting and explain how they work.

Answer 21

Bubble - goes through an array and compare two adjacent elements, swap the two elements if the order in which they’re in are not do not satisfy the results we’re looking for.

Selection - goes through an array at every element and looks for any value that is smaller/larger (depending on what ways we’re sorting), if there’s one value that is smaller/larger, swap them.

Question 22

List two types of searching and explain how they work.

Answer 22

Sequential - goes through the array and finds the target value
Binary (requires an sorted list) - Starts in the middle of the array and checks if the desired result is in the first or second half of the list by comparing whether the target value is smaller than or larger than the middle value. The other half is then discarded and the process is used for this sub-array until there is only one element left.