jquery open select dropdown code example
Example 1: jquery dropdown select
$('select>option:eq(3)').prop('selected', true);
Example 2: open select dropdown
$('#MyButton').on("click",function(){
$("#selecttest").attr("size", 8);
$("#selecttest").css("position","fixed");
$('#MyButton').css("margin-left", $("#selecttest").width() + 5);});
$('#selecttest').on("change",function(){
$("#selecttest").attr("size", 1);});
Example 3: jquery select dropdown
$('#mySelectElement option')[0].selected = true;
Example 4: open select dropdown
var myDropDown=$("#myDropDown");
var length = $('#myDropDown> option').length;
myDropDown.attr('size',length);