5. Buttons and Selection Quiz

5.1. Question 1

What is the primary operational difference between the .is_pressed() method and the .was_pressed() method?

They are identical methods and can be used completely interchangeably.

Incorrect. They track button states using different historical timing logic.

.is_pressed() checks if the button is down at that exact moment, while .was_pressed() checks if it was pressed since the last time the code checked.

Correct. The text outlines that .is_pressed looks at the active moment, whereas .was_pressed tracks state history since the last device check.

.was_pressed() only works if the micro:bit is powered off.

Incorrect. Both require active live execution on powered hardware.

.is_pressed() triggers an automatic 1000ms delay internally.

Incorrect. Any delays must be programmed explicitly using sleep statements.

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5.2. Question 2

What data type is returned when evaluating a button checking method like button_a.is_pressed()?

String

Incorrect. It does not return text characters inside quotation marks.

Integer

Incorrect. It does not output raw whole numbers like 1 or 0.

Boolean

Correct. The documentation explicitly states that it returns either True or False.

Float

Incorrect. It does not return fractional decimal numbers.

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5.3. Question 3

Look at the following selection control block code:

if button_a.is_pressed():
    display.show("A")
elif button_b.is_pressed():
    display.show("B")

What occurs if a user presses both Button A and Button B down at the exact same fraction of a second?

The micro:bit displays the character “A” and then immediately flashes “B”.

Incorrect. An if-elif chain stops evaluating after finding its first matching match.

Only the letter “A” is shown on the display.

Correct. Because the if condition is evaluated first, its block triggers and the elif branch for Button B is skipped entirely.

The display panels clears itself automatically due to a runtime error.

Incorrect. This is structured logically and will not crash.

A new custom combination image is drawn onto the screen matrix.

Incorrect. No graphic combinations occur unless explicitly programmed.

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5.4. Question 4

Which of the following code patterns checks if BOTH buttons are being held down simultaneously?

if button_a.is_pressed() and button_b.is_pressed():

Correct. The and logical operator requires both individual button states to evaluate to True at the same time.

if button_a.is_pressed() or button_b.is_pressed():

Incorrect. The or operator requires only one or the other button to be down, not necessarily both.

if button_a.is_pressed() + button_b.is_pressed():

Incorrect. Combining button conditional methods with addition operators is improper syntax.

if button_a.was_pressed() or button_b.was_pressed():

Incorrect. This checks if either button had a historical click event independently.

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5.5. Question 5

What is the purpose of using the min() and max() functions when updating game variables like a guess_number?

To increase the execution speed of the tracking loop.

Incorrect. Math boundaries do not alter physical code execution velocities.

To set upper and lower boundaries (limits) so the variable doesn’t go out of bounds.

Correct. The tasks demonstrate using functions like min(9, guess_number + 1) to prevent values from skipping outside specified limits.

To clear out old values stored inside the micro:bit system memory.

Incorrect. Variable cleanup is handled natively by the runtime environment.

To display multiple integers simultaneously on a single screen framework.

Incorrect. Numeric display limits are dictated by matrix resolutions.

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5.6. Question 6

Consider the following program loop:

while True:
    if button_a.was_pressed():
        display.show("A")
    else:
        sleep(100)

Why is the sleep(100) statement placed inside the else: clause block?

To speed up the processing capability of the selection structure.

Incorrect. Sleeping intentionally slows processing down.

To clear out any existing images currently rendering on the grid matrix.

Incorrect. Clearing requires explicit command lines like display.clear().

To give the system a short rest and save processing resources when no button actions are happening.

Correct. It stops the loop from running at maximum speed when idle, which provides efficiency pauses.

To force the loop condition to evaluate as False and exit.

Incorrect. A while True container loops infinitely until forced by a break statement.

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5.7. Question 7

What happens to the internal click history counter immediately after you call the button_a.was_pressed() method?

The history counter doubles its tracking capacity automatically.

Incorrect. It does not accumulate continuously after interrogation.

The counter resets back to False.

Correct. Calling .was_pressed() clears the history buffer status so it can start fresh tracking for future clicks.

The micro:bit pauses execution mechanics for exactly 1000ms.

Incorrect. System delays are governed strictly by sleep statements.

The button stops accepting any new real-world physical interactions.

Incorrect. Buttons stay continuously receptive during standard loop cycles.

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5.8. Question 8

A student writes the code block below to increase a score value when pressing Button A:

# Start value
score = 5
if button_a.was_pressed():
    score = min(9, score + 2)

If the current value of score is 8, and the user presses Button A, what is the new value stored inside score?

10

Incorrect. The bounding check sets a structural cap that prevents it from reaching 10.

8

Incorrect. The baseline number increases because it has space before hitting the absolute ceiling limit.

9

Correct. Adding 2 to 8 yields 10, but min(9, 10) returns 9, limiting the value to the max boundary.

5

Incorrect. The value updates upward rather than resetting to its base initial state.

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5.9. Question 9

Which of the following code blocks demonstrates the correct way to continuously decrease a variable called level by a step of 1 down to a minimum floor value of 1 using Button B?

if button_b.was_pressed():
    level = max(1, level - 1)

Correct. Subtracting 1 decreases the value, and passing it to max(1, ...) ensures it cannot fall below 1.

if button_b.was_pressed():
    level = min(1, level - 1)

Incorrect. This forces the level to immediately drop to 1 or lower.

if button_b.is_pressed():
    level = max(9, level + 1)

Incorrect. This adds to the level variable and checks against an incorrect upper constraint.

if button_b.was_pressed():
    level = level - 1

Incorrect. This fails to implement a safety ceiling or floor value constraint entirely.

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5.10. Question 10

If you run code that contains an infinite while True: loop without adding any internal sleep() delays or scrolling actions, what is the resulting negative outcome?

The Python editor automatically deletes the script files from storage.

Incorrect. Program tracking logic does not modify code storage spaces.

The micro:bit changes its display parameters to reverse text orientation.

Incorrect. Formatting layouts are not dynamically inverted by processor load.

The processor will run continuously at maximum capacity without a rest, wasting power.

Correct. Including minor delay offsets keeps processing loops efficient.

The hardware permanently locks up and can never be reprogrammed.

Incorrect. Micro:bits can always be safely rewritten with fresh code flashing sequences.