3.1 Variables Assignment 1 Hacks

  1. You want to store the number of apples in a shop. What is the best variable name and data type?

Answer: numApples and integer

EXPLANATION: the number of apples is a whole number, so it is best expressed as an integer.

  1. You are storing true or false in a variable that asks if the classroom is cold. What is the best variable name and data type?

Answer: isCold and boolean

EXPLANATION: the state of being cold is a binary setting (either true or false), which is why it should be boolean.

  1. How do you store the ID numbers for the students in the classroom? Choose the best variable name and data type

Answer: IDnumber and string

EXPLANATION: the ID number is constantly changing and is a list of numbers next to each other, so instead of an integer, it is best expressed as a string.

  1. Is itisRainingtodayinsandiego a better option than isRaining?

Answer: no

EXPLANATION: this is way too complicated, isRaining is much simpler and broader

  1. Which of the following types of data is best for a true or false question?

Answer: Boolean

EXPLANATION: Boolean is true/false

  1. What is the difference between an integer and string of numbers?

Answer: An integer can be changed with addition and subtraction and a string is a set number or string of letters.

3 Practice Questions

  1. What is the best way to determine if John was money?

isMoney, boolean

  1. What is the best way to determine Manny’s phone number?

phoneNumber, string

  1. What is the best way to store all of Felipe’s pets?

petsOwned, string

3.1 Variables and Assignment Video 2 Hacks

  1. Consider the following code segment: currentScore ⟵ 10

    highScore ⟵ currentscore

    currentScore ⟵ 7

    Answer:

    currentScore = 7

    highScore = 10

  2. Consider the following code segment: num1 ⟵ 4

    num2 ⟵ 6

    num1 ⟵ num 2

    Answer:

    num1: 6

    num2: 6

  3. Consider the following code segment: num1 ⟵ 25

    num2 ⟵ 15

    num3 ⟵ 30

    num2 ⟵ num3

    num3 ⟵ num1

    num1 ⟵ num2

    Answer:

    num1: 30

    num2: 30

    num3: 25

  4. Consider the following code segment: p ⟵ 10

    q ⟵ 20

    r ⟵ 30

    s ⟵ 40

    p ⟵ q

    q ⟵ r

    s ⟵ q

    r ⟵ p

    Answer:

    r = 20

  5. Consider the following code segment first ⟵ true

    second ⟵ false

    second ⟵ first

    first ⟵ second

    Answer:

    first: true

    second: true

  6. Consider the following code segment a ⟵ 10

    b ⟵ 20

    c ⟵ 30

    d ⟵ 40

    x ⟵ 20

    b ⟵ x + b

    a ⟵ x + 1

    d ⟵ c / d + 2

    Answer:

    a = 21

    b = 40

    c = 30

    d = 50

3.2 Data Abstraction Video 2 Hacks

  1. Consider the following code segment scores1 <- [89, 78, 92, 63, 95, 88]

    scores2 <- [92, 79, 97, 63]

    scores1 <- scores2

    Answer:

    score2 = [92, 79, 97, 63]

  2. Consider the following code segment listA <- [“Sam”, “Ann”]

    listB <- [“Jamal”, “Tamara”]

    listB <- listA

    listA <- listB

    Answer:

    listA = [“Sam”, “Ann”]

  3. Consider the following code segment [“Red”, “Orange”, “Yellow”, “Green”, “Blue”, “Purple”]

    Answer:

    The length of the list is 6

  4. What is the index number of “Purple” in this list? [“Red”, “Orange”, “Yellow”, “Green”, “Blue”, “Purple”]

    Answer:

    6

    Correct Answer:

    5 because it starts with 0

  5. Which of the following types of data can be stored in a list?

    Answer:

    Booleans, Strings, and Floats

  6. Which of the following variables is a float?
    • Apples
    • -106.2
    • 34
    • True

    Answer:

    -106.2 because thats the only decimal

  7. If a list has a length of 24 items, what is the index number of the 17th item?
    • 21
    • 17
    • 16
    • 69

    Answer:

    16 because first one is 0

  8. A variable is permanent and cannot be changed later on.
    • True
    • False

    Answer:

    False

  9. Which of the following is true about the list? [“Apples”, 42.0, “Bananas”, 0.5, “Avocado”, -902.2, “Lychee”, 6.9, “Orange”, 7.2]

    Answer:

    The list has floats, strings, and the index of “Avocado” is also 4