pxt-calliope/docs/projects/coin-flipper.md

Coin Flipper

Introduction @unplugged

Let's create a coin flipping program to simulate a real coin toss. We'll use icon images to represent a heads or tails result.

Step 1

Get an ||input:on button A pressed|| block from the ||input:Input|| drawer in the toolbox. We'll put our coin flipping code in here.

input.onButtonEvent(Button.A, ButtonEvent.Click, () => {
})

Step 2

Grab an ||logic:if else|| block and set it inside ||input:on button A pressed||. Put a ||Math:pick random true or false|| into the ||logic:if|| as its condition.

The ||Math:pick random true or false|| returns a random true or false value which we use to determine a heads or tails result for a coin toss.

input.onButtonEvent(Button.A, ButtonEvent.Click, () => {
    if (Math.randomBoolean()) {
    } else {
    }
})

Step 3

Now, put a ||basic:show icon|| block inside both the ||logic:if|| and the ||logic:else||. Pick images to mean heads and tails.

input.onButtonEvent(Button.A, ButtonEvent.Click, () => {
    if (Math.randomBoolean()) {
        basic.showIcon(IconNames.Skull)
    } else {
        basic.showIcon(IconNames.Square)
    }
})

Step 4

Press button A in the simulator to try the coin toss code.

Step 5

You can animate the coin toss to add the feeling of suspense. Place different ||basic:show icon|| blocks before the ||logic:if|| to show that the coin is flipping.

input.onButtonEvent(Button.A, ButtonEvent.Click, () => {
    basic.showIcon(IconNames.Diamond)
    basic.showIcon(IconNames.SmallDiamond)
    basic.showIcon(IconNames.Diamond)
    basic.showIcon(IconNames.SmallDiamond)
    if (Math.randomBoolean()) {
        basic.showIcon(IconNames.Skull)
    } else {
        basic.showIcon(IconNames.Square)
    }
})

Step 6

If you have a @boardname@, connect it to USB and click |Download| to transfer your code.

Step 7

Press button A for a flip. Test your luck and guess heads or tails before the toss is over!