Dynamic <select> with Zurb Foundation Custom Forms. Requires jQuery.

foundation-dropdown.js

var selectvalues = { "1": "item 1", "2": "item 2", "3": "item 3"};
var $dropdown = $('#dropdown'); 
$.each(selectvalues, function(key, value) {
  // add to dropdown
  $dropdown
    .append($('<option>', { value : key })
      .text(value));
});
// refresh the elements on zurb dropdown
Foundation.libs.forms.refresh_custom_select($dropdown, true);