Chapter 2 - Iteration

Question 1

What is iteration?

Answer 1

A procedure or set of commands that are repeated either a set number of times or while a condition is met.

Question 2

What is definite iteration?

Answer 2

This is when the number of loops is known before the loop is started, e.g. a for loop

Question 3

What is Indefinite iteration?

Answer 3

This is when a number of loops is not known before the loop is started

Question 4

Give an example of definite iteration

Answer 4

for i in range(s):
print(‘Hello!’)

Question 5

Give an example of indefinite iteration

Answer 5

a = 3
while a < 10:
print(‘a is currently: ‘ + a)
a += 1

Question 6

Is a for loop definite or indefinite iteration

Answer 6

definite

Question 7

is a while loop definite or indefinite iteration

Answer 7

indefinite

Question 8

is a do…. until loop definite or indefinite iteration

Answer 8

indefinite

Question 9

The condition-check in an indefinite iteration loop can contain several layers of what?

Answer 9

boolean logic

Question 10

how may a programmer create a script?

Answer 10

1. come up with an idea or be given a brief by a company
2. sketch out a plan of the script using a list algorithm or flow diagram
3. Convert plan to pseudo code
4. write the script
5. perform a dry run using a trace table
6. test and analyse results
7. improve code and repeat step 6

Question 11

what is a syntax error

Answer 11

an error in the code cause by a spelling mistake, grammatical mistake or indentation error etc.

Question 12

what is a logical error

Answer 12

the code does work but not as intended

Question 13

what is a dry run

Answer 13

the script is run on paper and each stage is carefully analysed to see what values the various variables and outputs have

Question 14

what is a trace table

Answer 14

the table that keeps track of the variables and outputs during a dry run