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docs/reference/input/on-button-pressed.md

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+# On Button Pressed
+
+Register an [event handler](/microbit/reference/event-handler) that will execute whenever an input button (A, B, or A and B together) is pressed during program execution. When [running code](/microbit/js/simulator) with this function in a web browser, click an on-screen input button - labelled A or B.
+
+```sig
+input.onButtonPressed(Button.A, () => {})
+```
+
+### Example: count button clicks
+
+This example counts how many times the left or right input button is pressed. Each time a button is pressed, the global count variable is increased by 1 and displayed on the screen.
+
+```blocks
+let count = 0
+basic.showNumber(count)
+input.onButtonPressed(Button.A, () => {
+    count++;
+    basic.showNumber(count);
+})
+```
+
+### Example: roll a dice
+
+This example generates a random number when you press the B input button, and then displays a random die image:
+
+```blocks
+input.onButtonPressed(Button.B, () => {
+    let dice = Math.random(6)
+    basic.showNumber(dice)
+})
+```
+
+### Lessons
+
+[smiley](/microbit/lessons/smiley), [answering machine](/microbit/lessons/answering-machine), [screen wipe](/microbit/lessons/screen-wipe), [rotation animation](/microbit/lessons/rotation-animation)
+
+### See also
+
+[button is pressed](/microbit/reference/input/button-is-pressed), [forever](/microbit/reference/basic/forever)
+