2016-03-26 00:47:20 +01:00
|
|
|
# counter activity
|
|
|
|
|
|
|
|
Display a number with a variable.
|
|
|
|
|
|
|
|
### ~avatar avatar
|
|
|
|
|
|
|
|
### @video td/videos/counter-0
|
|
|
|
|
|
|
|
Welcome! This tutorial will teach you how to make a counter that increments when button A is pressed. Let's get started!
|
|
|
|
|
|
|
|
### ~
|
|
|
|
|
|
|
|
To create a new script, go to the [Create Code](/microbit/create-code) page and tap *New Project* under **Touch Develop**.
|
|
|
|
|
|
|
|
Let's start by creating a **local variable** `count` to keep track of the current count.
|
|
|
|
|
|
|
|
```
|
|
|
|
let count = 0
|
|
|
|
```
|
|
|
|
|
|
|
|
The code under ``on button pressed("A")`` will run each time the user presses A. Let's add a line of code that increments `count` by `1`.
|
|
|
|
|
|
|
|
```
|
|
|
|
let count_ = 0
|
2016-03-30 06:17:57 +02:00
|
|
|
input.onButtonPressed(Button.A, () => {
|
2016-03-26 00:47:20 +01:00
|
|
|
count = count + 1
|
|
|
|
})
|
|
|
|
```
|
|
|
|
|
|
|
|
Since the count has changed, it's time to refresh the screen display. Let's add a line of code to display the count on screen.
|
|
|
|
|
|
|
|
```
|
|
|
|
let count_1 = 0
|
2016-03-30 06:17:57 +02:00
|
|
|
input.onButtonPressed(Button.A, () => {
|
2016-03-26 00:47:20 +01:00
|
|
|
count = count + 1
|
|
|
|
basic.showNumber(count, 150)
|
|
|
|
})
|
|
|
|
```
|
|
|
|
|
|
|
|
### ~avatar avatar
|
|
|
|
|
|
|
|
Excellent, you're ready to continue with the [challenges](/microbit/lessons/counter/challenges)!
|
|
|
|
|
|
|
|
### ~
|
|
|
|
|