Question

I have been breaking down Twitter Bootstap and was wondering what the relation is between the 290 : 330.

I know that 330 is the number of pixels scrolled when the sidebar becomes fixed. Thanks!

// side bar
$('.bs-docs-sidenav').affix({
  offset: {
    top: function () { return $window.width() <= 980 ? 290 : 330 }
  , bottom: 270
  }
})

Answer 1

It means if $window.width() is less than or equal to 980 then (?) use top offset of 290, else (:) use top offset of 330.

The same thing could have been written as:

top: function () { 
    if ($window.width() <= 980) {
        return 290;
    } else {
        return 330;
    }
}