pxt-calliope/docs/reference/js/lessons/looper/challenges.md
2016-03-25 16:47:20 -07:00

1.7 KiB

looper challenges

Coding challenges for the looper tutorial. #docs

Before we get started

Complete the following guided tutorial:

At the end of the tutorial, click keep editing. Your code should look like this:

for (let i = 0; i < 6; i++) {
    basic.showNumber(i, 150)
    basic.pause(2000)
}

Challenge 1

@video td/videos/looper-1

What if we want to count up to lucky number 7 instead? Let's do that by changing the ending value to 8 instead of 6.

for (let i1 = 0; i1 < 8; i1++) {
    basic.showNumber(i1, 150) // ***
    basic.pause(2000)
}
  • Run the program now to see your changes.

Challenge 2

@video td/videos/looper-2

What about 9? Let's do that by changing the ending value to 10.

for (let i2 = 0; i2 < 10; i2++) {
    basic.showNumber(i2, 150)
    basic.pause(2000)
}
  • Run your code to see the new counter.

Challenge 3

@video td/videos/looper-3

Now let's start counting from 3 instead! Our for loop will always start at 0 so we simply add 3 to the i variable when passing it to basic->show number.

for (let i3 = 0; i3 < 8; i3++) {
    basic.showNumber(i3 + 3, 150) // ***
    basic.pause(2000)
}

Run it on the simulator!

Challenge 4

@video td/videos/looper-4

Now, let's count down from 9. Change the line basic->show number(i + 3, 150) to basic->show number(9 - i, 150).

for (let i4 = 0; i4 < 10; i4++) {
    basic.showNumber(9 - i4, 150) // ***
    basic.pause(2000)
}
  • Run the code to make sure it is doing what is expected.

Challenge 5

After counting down from 9 let's show the string BOOOM!