R354 - CTAP2 Computational Thinking, Algorithms and Programming 2

Variable

A named location in memory. Storing a single piece of data, which can be changed during run time.

Create a variable named year and assign it to the value of the current year as an integer

year = 2024 OR year = int(2024)

What is the value of num3 when this code has executed?
num1 = 5
num2 = 10
num3 = num1*num2

50

What is the value of num3 when this code has executed?
num1 = 21
num2 = 7
num3 = num1/num2

3.0 (results of division are stored as floats/real)

When programming what do we use the * operator for?

Multiplication

In the example below what does the + represent?
num3 = num1+num2

Addition

In the example below what does the + represent?
firstName = 'Ada'
surname = 'Lovelace'
fullName = firstName + ' ' + surname

Concatenation (joining of strings)

When programming what do we use the / operator for?

Division

When programming what do we use the - operator for?

Subtraction

When programming what do we use the == operator for?

Equal to

When programming what do we use the != operator for?

Not equal to

When programming what do we use the > operator for?

Greater than

When programming what do we use the >= operator for?

Greater than or equal to

When programming what do we use the < operator for?

Less than

When programming what do we use the <= operator for?

Less than or equal to

What python keyword do you use to accept data from user into your program?

Input

Write the code to ask the user for a number and store it as a variable named guess

guess = int(input("Enter your number: "))
#It doesn't matter if you wrote something else in the brackets but the "" do!

What python keyword do you use to output data from your program to your user?

Print

Complete the code below to output Hello followed by their name:

name = input("What's your name?")
#your code goes here

print("Hello", name)
OR
print("Hello "+name)

What type of data does an integer hold?

Whole numbers (including negative numbers and 0)

What type of data does a float/real hold?

Decimal numbers

What type of data does a string hold?

Text, punctuation, numbers, symbols - anything stored in a ""

What type of data does a Boolean hold?

True / False
1 / 0

What is the output of the code below?
print(int(101.1))

101 (casting a float as an integer will remove the decimal numbers)

What is the output of the code below?
print(int(42.99))

42 (casting a float as an integer will remove the decimal numbers)

Define the term casting

Changing a variable's data type

What is a list used for?

Storing multiple pieces of data under a single name.

example:
Names
Lucki
Matt
Hiten
Aoife

Define the term sequence

Executing instructions in order

Define the term syntax error

An error that does cause the program to crash. An error in the rules of the programming language.

Define the term logic error

An error that does not cause the program to crash or produces unexpected output

Define the term IDE (Integrated Development Environment)​

Allows programmers to write, test and run their programs. ​

Define the term selection

A comparison is made and the algorithm branches based on the result (can execute different pieces of code)

What is the output of this code?
number = 5
if number < 10:
number = number * 2
else:
number = number / 2
print(number)

10

What is the output of this code?
number = 18
if number < 10:
number = number * 2
else:
number = number / 2
print(number)

9

What do all selection statements start with?

if

What key term is missing from the code extract below?

if number < 5:
print("your number is less than 5")
____ number < 10:
print("Your number is less than 10")

elif

What key term is missing from the code extract below?

if number =< 5:
print("your number is 5 or less")
____:
print("Your number is greater than 5")

else

Does else have a condition?

No

How many If statements can you have in 1 block of selection statements?

1 (if starts a new selection block)

How many elif statements can you have in 1 block of selection statements?

Unlimited

Define the term iteration

Part of an algorithm is looped if a certain condition is met

Name the 2 types of loop

while and for

Name the boolean operators you can use in a program

AND, OR, NOT

Why should you use comments in your code?

Make it easier to follow the logic of your code.
Explain how the code works.
Add details like the version number.
To help someone else edit your code or to help someone else edit your code (maintainability)

What numbers will this code output?

for count in range(0,10):
print(count)

0
1
2
3
4
5
6
7
8
9

A for loop is what type of loop?

Counter controlled Iteration / loop

A while loop is what type of loop?

Conditional iteration / loop

Define compression

Reducing the size of a fil4

Name the 2 types of compression

Lossy and Lossless

Define lossy compression

Compression in which data is lost and cannot be retrieved in its original form.

Define lossless compression

Compression in which no data is lost and all data can be retrieved in its original form.

What type of file would you use lossy for?

Used for media (images, videos, sound) where a loss of detail isn't noticeable to the eye/ear.

What type of file would you use lossless for?

Text and programs as a loss of data means the file wouldn't work correctly.

Why do we compress files?

Reduce the file size
Less data means the file is quicker to send
Means you can store more files on secondary storage

Define the term bit

A single binary digit, either 1 or 0

Define the term byte

8 bits of data

Define the term nibble

4 bits of data

How many nibbles in a byte?

2 (1 nibble is 4 bits, 1 byte is 8 bits therefore 8 / 4 is 2)

When storing data, what does KB stand for?

Kilobyte

When storing data, what does GB stand for?

Gigabyte

When storing data, what does MB stand for?

Megabyte

How many bytes in a kilobyte?

1024

Order these storage units from smallest to biggest: nibble, bit, kilobyte, gigabyte, byte, megabyte

bit, nibble, byte, kilobyte, megabyte and gigabyte

Order these storage units from largest to smallest: nibble, bit, kilobyte, gigabyte, byte, megabyte

Gigabyte, megabyte, kilobyte, byte, nibble and bit

How many kilobits in a megabyte?

1024

How many megabytes in a gigabyte?

1024