pxt-calliope/docs/reference/js/lessons/while-counting/challenges.md

digi yoyo challenges

These challenges will teach you how to create a counter 10 to 1. #docs

Challenge 0

@video vimeo/134459911

This guided tutorial will teach you how to make a counter from 0-9 using a while loop.

count = 1
while (count < 10) {
    basic.pause(1000)
    basic.showNumber(count, 150)
    count = count + 1
}

Challenge 1

How about we create a counter that counts backwards from 10 to 1? Let's add a while loop that executes only when count is greater than 0.

count = 1
while (count < 10) {
    basic.pause(1000)
    basic.showNumber(count, 150)
    count = count + 1
}
while (count > 0) {
}

Challenge 2

Inside of the while loop, let's add pause->(1000) so that we have a pause between each number as it's counting down. Also, let's show count!

count = 1
while (count < 10) {
    basic.pause(1000)
    basic.showNumber(count, 150)
    count = count + 1
}
while (count > 0) {
    basic.pause(1000) // ***
    basic.showNumber(count, 150) // ***
}

• Run the code to see if it works as expected.

Challenge 3

@video vimeo/134449661

Now, we need count to decrease by one after the micro:bit has displayed the value of count.

We can do this by adding this line:

count = count - 1