pxt-calliope/olddocs/lessons/rotation-animation/quiz-answers.md

rotation animation quiz answers

Learn how to create a rotating image with a while loop.

This is the answer key for the rotation animation quiz.

1. What is a " variable"?

Answers may vary. A variable is a place where you can store data so that you can use it later in your code.

2. Write the code to create a ** variable** called foo that stores a boolean and initialize it to false.

let rotating = true;

3. Explain what this line of code does.

let rotating = true;
while (rotating) {
    basic.showLeds(`
        . . . . .
        . . . . .
        . . # . .
        . . . . .
        . . . . .
        `)
    basic.showLeds(`
        . . . . .
        . . . . .
        . . . . .
        . . . . .
        . . . . .
        `)
}

It is a while loop that will be executed only if the ** variable** called rotating is true.

4. If the rectangle below represents the BBC micro:bit, shade the areas that will be displayed. Explain why that particular area is shaded.

basic.showLeds(`
        . . # . .
        . . # . .
        . . # . .
        . . # . .
        . . # . .
        `)
basic.showLeds(`
        . . . . .
        . . . . .
        # # # # #
        . . . . .
        . . . . .
        `)
basic.showLeds(`
        . . . . #
        . . . # .
        . . # . .
        . # . . .
        # . . . .
        `)
basic.showLeds(`
        . . . . #
        . . . # .
        . . # . .
        . # . . .
        # . . . .
        `)
   

Show animation will show a series of image frames on the LED screen, pausing the specified time (400 milliseconds) after each frame