2 Flow Control

Question 1

What are the two values of the Boolean data type? How do you write them?

Answer 1

True

False

Question 2

What are the three Boolean operators?

Answer 2

And
Or
Not

Question 3

Write out the truth tables of each Boolean operator (that is, every possible combination of Boolean values for the operator and what they evaluate to).

Answer 3

And: 
True and True -> True
True and False > False
False and True -> False
False and False -> False

Or:
True or True -> True
True or False -> True
False or True -> True
False or False -> False

Not:
Not True -> False
Not False -> True

Question 4

What are the six comparison operators?

Answer 4

==
=!
<
<
>=
<=

Question 5

Explain what a condition is and where you would use one.

Answer 5

E.g. boolean expressiones/ operators.

Conditions always evaluate down to True or False and thus decide which part of the code is executed

Question 6

Name three flow control statement types and state what they are made of

Answer 6

1. If
2. While loop -> while true
3. For loop -> for a certain number

They often start with a condition, which is always followed by the clause (block of code)

Question 7

What keys can you press if your program is stuck in an infinite loop?

Answer 7

ctrl + c

Question 8

What is the difference between break and continue?

Answer 8

Both are used inside loops.
Continue: program execution jumps back to the start of the loop
Break: program execution jumps out of the loop

Question 9

What does this code evaluate to?

x = [[1, 2], [3, 4]]
for x in x:
for x in x:
print(x)

How could you write this code in one line?

Answer 9

x = [[1, 2], [3, 4]]
for x in x:
for x in x:
print(x)

Evaluates to:
1
2
3
4

One line:
x for x in x for x in x

Question 10

numbers=[‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’]
letters=[‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’, ‘g’, ‘h’]

How can you create a list, that has as many list as there are numbers, and as many values as there

Answer 10

numbers=[‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’]
letters=[‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’, ‘g’, ‘h’]

spam = []
for nr in numbers:
    spam.append(list())
    for letter in letters:
        spam[-1].append(nr + letter)        
print(spam)