pxt-calliope/docs/reference/js/lessons/break/challenges.md

break challenges

This guide will show you how to use a break statement within a while loop. #docs

Challenge 0

Welcome! This guided tutorial will assist you with this activity.

count = 0
shouldBreak = false
input.onButtonPressed("A", () => {
    shouldBreak = true
})
while (true) {
    if (shouldBreak) {
        basic.showString("I'M OUT!", 150)
        images.createImage(`
# . . . #
# . . . #
. . # . .
# . . . #
. # # # .
`).showImage(0)
        break
    }
    count = count + 1
    basic.showNumber(count, 150)
    basic.pause(1000)
}

Challenge 1

Try to remove the break in the if loop. What problem does this create?

Challenge 2

Now let's resume the timer again once button B is pressed! To do so, begin by creating a condition to know when button B is pressed.

// **. . .**
while (true) {
    if (shouldBreak) {
        basic.showString("I'M OUT!", 150)
        break
    }
    count = count + 1
    basic.showNumber(count, 150)
    basic.pause(1000)
}
input.onButtonPressed("B", () => {
}) // ***

Next, set shouldBreak back to false to indicate we want to run the while loop again.

// **. . .**
input.onButtonPressed("B", () => {
    shouldBreak = false // ***
})

And now copy the code from the previous while loop into the condition of input->on button pressed("B"). This will resume the counter.

// **. . .**
input.onButtonPressed("B", () => {
    shouldBreak = false
    while (true) {
        if (shouldBreak) {
            basic.showString("I'M OUT!", 150) // ***
            break // ***
        }
        count = count + 1 // ***
        basic.showNumber(count, 150) // ***
        basic.pause(1000) // ***
    }
})

Challenge 3

Notice that the two while loops are identical. Clean up this redundancy in your code by creating another method and then placing the while loop in the method.