Javascript, passing my string as an argument turns it to a 0

I'm using scrollmagic.io and am making an anchor navigation menu. I'm following this tutorial. The scroll works! Except it was scrolling back to the beginning and not to the page it should be at.

Here is my code:

// init controller
var controller = new ScrollMagic.Controller();

// animate scroll instead of a jump
controller.scrollTo(function(target) {
  console.log('scroooooll');
  console.log('target = '+target); // THIS IS PRINTING 0
  console.log(typeof(target));
  /* Commenting out what it should do for simplicity. */
});

// scroll action when you click the nav links
$(document).on('click', 'a[href^=#]', function(e) {
  var id = $(this).attr('href'); // get the href of clicked link
  if ($(id).length > 0) { // not empty links
    e.preventDefault(); // prevent normal link action

    // this is the function call
    console.log('click');
    console.log('id = '+id); // IT PRINTS CORRECT HERE
    console.log(typeof(id));
    controller.scrollTo(id); // scroll on click

    // update the URL
    if (window.history && window.history.pushState) {
      history.pushState("", document.title, id);
    }
  }
});

And here is the output of my console log:

click
id = #{the-href-value}
string
scroooooll
target = 0
number

My Javascript is pretty rusty, but this doesn't seem right to me. Why is it changing my variable from a string to a 0 when I pass it as a parameter?

Solution

From the documents:

"This function will be used for future scroll position modifications. This provides a way for you to change the behaviour of scrolling and adding new behaviour like animation. The function receives the new scroll position as a parameter and a reference to the container element using this. It may also optionally receive an optional additional parameter (see below)"

So, the first parameter is passed by controller. You will get your parameter after that.

http://scrollmagic.io/docs/ScrollMagic.Controller.html#scrollTo

Try printing console.log(args);

controller.scrollTo(function(scrollPos, targetHrefISent) {
  console.log('scroooooll');
  console.log('target = '+targetHrefISent); // THIS IS PRINTING 0
  console.log(typeof(targetHrefISent));
  /* Commenting out what it should do for simplicity. */
});