02 Section 5 - Program flow, Boolean operators and Arrays

Question 1

What do IF statements allow a programmer to do?

Answer 1

To check if a condition is true or false, and carry out different actions depending on the outcome

Question 2

What structure do IF statements normally have?

Answer 2

IF … THEN:

ElSE:

Question 3

When is ELSE not needed in an IF statement?

Answer 3

If there is nothing for the program to do when the condition is false then leave out the ELSE part

Question 4

What is a nested IF statement?

Answer 4

A more complex IF statement, made by putting one IF statement inside of another

Question 5

What do nested IF statements allow you to do?

Answer 5

-check more conditions once you have established the previous condition is true

Question 6

What are IF-ELSEIF statements used for?

Answer 6

To check multiple conditions

-only check more conditions if the previous condition is false

Question 7

What are SWITCH-CASE statements?

Answer 7

statements that can check whether a variable has specific values

Question 8

When are SWITCH-CASE statements used?

Answer 8

When you want a program to perform different actions for different values of the same variable

Question 9

What is the structure of SWITCH-CASE statements?

Answer 9

SWITCH … :
CASE … :
CASE … :
ENDSWITCH

Question 10

What is the drawback of SWITCH-CASE statements?

Answer 10

They can only check the value of one variable

IF-ELSEIF statements can check if multiple conditions are true

Question 11

What are FOR loops?

Answer 11

An example of count-controlled loops
They will repeat the code inside of them for a fixed number of times
-the number of times they are repeated depends on an initial value, end value and step count (can also be set as the program runs by using a variable as the number)

Question 12

What is the structure of FOR loops?

Answer 12

FOR i in RANGE():

NEXT i

Question 13

What are the different types of loops you can have that are controlled by conditions?

Answer 13

REPEAT … UNTIL

WHILE

DO WHILE

Question 14

What is an example of a count-controlled loop?

Answer 14

FOR loops

Question 15

What are the features of REPEAT loops?

Answer 15

• controlled by a condition at the end of the loop
• keep going until the condition is true (i.e. while it’s false)
• always runs the code inside at least once
• you can get an infinite loop if the condition is never true

Question 16

What are the features of WHILE loops?

Answer 16

• controlled by a condition at the start of the loop
• keep going while the condition is true (i.e. until it is false)
• never runs the code inside it if the condition is initially false
• get an infinite loop if the condition inside is always true

Question 17

What are the features of DO WHILE loops?

Answer 17

• controlled by a condition at the end of the loop
• keep going while the condition is true (i.e. until it’s false)
• always runs the code inside it at least once
• get an infinite loop if the condition is always true

Question 18

What is the structure of a REPEAT loop?

Answer 18

REPEAT
…
UNTIL condition

Question 19

What is the structure of a WHILE loop?

Answer 19

WHILE condition
…
ENDWHILE

Question 20

What is the structure of a DO WHILE loop?

Answer 20

DO
…
WHILE condition

Question 21

Whant are the 3 different Boolean operators?

Answer 21

AND
OR
NOT

Question 22

Why are Boolean operators used in conditions?

Answer 22

Boolean operators can be used to make all the different selection and iteration statements more efficient and versatile

Question 23

What are examples of selection statements?

Answer 23

IF-THEN-ELSE statements
Nested IF statements
IF-ELSEIF statements
SWITCH-CASE statements

Question 24

What are examples of iteration statements?

Answer 24

FOR loops
REPEAT loops
WHILE loops
DO WHILE loops

Question 25

What is an array?

Answer 25

It's a data structure that can store a collection of data values all under one name LISTS

Question 26

What is each piece of data in an array called?

Answer 26

an element

Question 27

How can an element of an array be accessed?

Answer 27

-each element can be accessed using its position (or index) in an array

Question 28

When should arrays be used?

Answer 28

When you have lots of related data that you want to store and it doesn't make sense to use separate variables

Question 29

How do you create an array?

Answer 29

``` ARRAY nameofarray[numberofvaluesinarray] nameofarray[0] = data nameofarray[1] = data nameofarray[2] = data ... ```

Question 30

How do you retrieve values from an array?

Answer 30

print(nameofarray[element'sposition])

Question 31

How do you change elements in an array?

Answer 31

nameofarray[element'sposition] = newdata

Question 32

What are two-dimensional arrays?

Answer 32

Like lists of lists, where each element of the one-dimensional array also has a one-dimensional array

Question 33

What is the position of an element in a two-dimensional array written as?

Answer 33

[a, b] or [a][b] where a represents the position in the one-dimensional array that the element is in and where b represents its position within that one-dimensional array