2.2.1. Programming Techniques

Question 1

What are the 3 programming constructs?

Answer 1

sequence selection iteration

Question 2

What are the 2 catagroies of loop iteration is split up into?

Answer 2

count controlled
condition controlled

Question 3

How does the selection programming construct work?

Answer 3

a certain block of code is run if a specific condition is met, using IF statements

Question 4

What is recursion?

Answer 4

a programming construct where a subroutine calls itself during its execution until the base case is met

Question 5

What is the base case in recursion?

Answer 5

a condition that must be met in order for the recursion to end

Question 6

What are 2 advantages of recursion?

Answer 6

1. can be represented in fewer lines of code
2. easier to express some function recursively than iteratively

Question 7

What are 3 disadvantages of using recursion?

Answer 7

inefficient use of memory
danger of stack overfow
difficult to trace

Question 8

What are 3 peices of information that are stored on the call stack?

Answer 8

parameters
return adresses
local variables

Question 9

What is the defenition of scope?

Answer 9

the section of the program where a variable can be accessed

Question 10

What are 3 advantages of using local variables over global variables?

Answer 10

less memory is used
self contained, so unaffected by code outside of the subroutine
takes precedence over global variables with the same name

Question 11

What is a top-down design? (2 things)

Answer 11

a technique used to modularise programs where the problem is continually broken down into sub-problems,

until each can be represented as an individual, self contained module that performs a certain task

Question 12

What are 3 advantages of a modular design?

Answer 12

1. greater reusability
2. makes a problem easier to understand and approach
3. testing and maintenance simplified as modules are self-contained

Question 13

What is the difference between procedures and functions?

Answer 13

functions must always return a value whilst a procedure does not

Question 14

What does it mean to pass a parameter to a subroutine by reference?

Answer 14

the memory address of the parameter is passed to the subroutine, so its value outside of the subroutine will be updated

Question 15

What are features of IDE’s?

Answer 15

debugging tools
source code editor
variables watch
stepping
breakpoint

Question 16

What does IDE stand for?

Answer 16

integrated development environment

Question 17

What is encapsulation in object-orientated programming?

Answer 17

where attributes are declared as private so can only be accessed and edited by public methods

Question 18

What is the purpose of encapsulation in object-orientated programming?

Answer 18

to reduce program complexity by protecting data from being accidentally edited by other parts of the program