6P.04 – Develop block-based programs using data types

Which of the following is an INTEGER?

• “8”

• 8

• “Hello”

• “A”

Answer explanation

The only INTEGER in the options is 8. The other choices are either strings ("8", "Hello", "A") or non-numeric values, making 8 the correct answer.

Which example is a STRING?

• 25

• -3

• “Raffles123”

• A

Answer explanation

A STRING is a sequence of characters enclosed in quotes. Among the options, "Raffles123" is the only one that meets this criterion, making it the correct choice.

Which data type is best to store a person’s initial (e.g., ‘A’)?

• Integer

• String

• Character

• Boolean

Answer explanation

The best data type to store a person's initial, like 'A', is 'Character'. This type is specifically designed to hold single characters, making it ideal for representing initials. Strings can also work, but 'Character' is more precise.

A variable “score” should be which type?

• Integer

• Character

Answer explanation

The variable 'score' should be an Integer because scores are typically represented as whole numbers, allowing for arithmetic operations. A Character type would not be suitable for numerical scoring.

Which operation can ONLY be used with integers?

• Adding two values

• Joining text

• Changing to uppercase

• Splitting letters

Answer explanation

Adding two values is an operation that can only be performed with integers, as it involves arithmetic. The other options—joining text, changing to uppercase, and splitting letters—are operations applicable to strings.

In Scratch, what happens if you try to add “5” (string) + 3 (integer)?

• Error

• Scratch converts “5” to 5 and adds → result 8

• Scratch converts 3 to “3” and joins → “53”

• Program crashes

Answer explanation

In Scratch, when adding a string "5" and an integer 3, the string is converted to a number. Thus, 5 + 3 equals 8, making the correct choice: Scratch converts "5" to 5 and adds → result 8.

What is the BEST data type to store a username?

• Integer

• Character

• String

• Boolean

Answer explanation

The BEST data type to store a username is a String, as usernames can contain letters, numbers, and special characters. Integers, Characters, and Booleans do not accommodate the diverse nature of usernames.

You want to check the first letter of a word. What data type is that letter?

• String

• Integer

• Character

• Loop

Answer explanation

The first letter of a word is a single character, which is represented as a 'Character' data type. In programming, a character is distinct from a string, which can contain multiple characters.

Which example shows the correct use of ALL THREE data types?

• name = “Amy”, age = “12”, grade = “A”

• name = Amy, age = 12, grade = A

• name = “Amy”, age = 12, grade = “A”

• name = A, age = “12”, grade = 10

Answer explanation

The correct choice is 'name = “Amy”, age = 12, grade = “A”' because it uses a string for 'name', an integer for 'age', and a string for 'grade', demonstrating all three data types correctly.

Why is choosing the correct data type important?

• It makes code look pretty

• It helps the program work correctly and avoid errors

• It makes the project smaller

• It removes the need for loops

Answer explanation

Choosing the correct data type is crucial because it ensures that the program operates as intended and minimizes the risk of errors. Using the right type helps in managing data effectively, leading to correct program behavior.