pxt-calliope/docs/projects/rock-paper-scissors.md
2017-09-11 10:49:40 -07:00

163 lines
3.5 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Rock Paper Scissors
## Step 1
We want the @boardname@ to choose rock, paper, or scissors when you shake it.
Place a ``||input:on shake||`` block so when you shake the @boardname@, it will run part of a program.
```blocks
input.onGesture(Gesture.Shake, () => {
})
```
## Step 2
Add a ``weapon`` variable to store a random number computed with ``||math:pick random||``.
When you shake the @boardname@, it should pick a random number from `0` to `2`
and store it in the variable `weapon`. (This variable is named `weapon` because
rock, paper, and scissors are the weapons you use to battle your friends!)
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
weapon = Math.random(3)
})
```
Each possible number these blocks can make (`0`, `1`, or `2`) means a different picture.
We will show the right picture for that number on the LED screen.
## Step 3
Place an ``if`` block under the ``||math:pick random||`` and
check whether ``weapon`` is equal to ``0``.
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
let weapon = Math.random(3)
if (weapon == 0) {
}
})
```
## Step 4
In the ``if`` block, place a ``||basic:show leds||`` block that shows a
picture of a piece of paper.
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
let weapon = Math.random(3)
if (weapon == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
}
})
```
## Step 5
Add an ``else if`` block to the ``if`` block and check whether ``weapon``
is equal to ``1``.
Click on the gearwheel icon to open up the ``if`` editor; then drag and drop an ``else if`` block in the ``if`` editor.
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
let weapon = Math.random(3)
if (weapon == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (weapon == 1) {
}
})
```
## Step 6
Place a ``||basic:show leds||`` block under the else if and draw a **rock** image on the screen.
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
let weapon = Math.random(3)
if (weapon == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (weapon == 1) {
basic.showLeds(`
. . . . .
. # # # .
. # # # .
. # # # .
. . . . .
`)
}
})
```
## Step 7
Add a ``||basic:show leds||`` block with a picture of scissors to the ``else`` part.
You don't need to check if `weapon` is `2` because `2` is the only number left out of `0`, `1`, and `2`.
That's why you can use an ``else`` instead of an ``else if``.
```blocks
let weapon = 0;
input.onGesture(Gesture.Shake, () => {
let weapon = Math.random(3)
if (weapon == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (weapon == 1) {
basic.showLeds(`
. . . . .
. # # # .
. # # # .
. # # # .
. . . . .
`)
} else {
basic.showLeds(`
# # . . #
# # . # .
. . # . .
# # . # .
# # . . #
`)
}
})
```
## Step 8
Your game is ready! Gather your friends and play Rock Paper Scissors!