deviceorientation not working

Question

Well I've got this little script:

<script>
window.addEventListener('deviceorientation', function(event) {
  var a = event.alpha;
  var b = event.beta;
  var g = event.gamma;
}, false);
</script>

<script>
setInterval('alert(""+g+"");', '1000');
</script>

Which should add the deviceorientation, attach it to the page, and alert every 1 second what the orientation currently is, the gamma.

It's not working, though? Nothing alerts! any tips... ideas...?

Edit: I get "Uncaught ReferenceError: g is not defined" in the console log... but it is defined!

Answer 1

The var statement sets the scope of a variable to the function it is in.

You are trying to access a local variable in the global scope—where it doesn't exist.

Additionally, you don't set the variable until a deviceorientation occurs, but you try to read it all the time.

You would have to rewrite your code like this:

<script>
window.addEventListener('deviceorientation', function(event) {

  var a = event.alpha;
  var b = event.beta;
  var g = event.gamma;

  console.log( g.toString() ); // Better to use a non-blocking method like console.log to display results.

}, false);
</script>