Related operation implementation code of JQuery select control_jquery

$ ("#select_id").change(function(){//code...}); //Add an event for Select, which is triggered when one of the items is selected
var checkText=$("#select_id"). find("option:selected").text(); //Get the Text selected by Select
var checkValue=$("#select_id").val(); //Get the Value selected by Select
var checkIndex =$("#select_id ").get(0).selectedIndex; //Get the index value selected by Select
var maxIndex=$("#select_id option:last").attr("index"); // Get the maximum index value of Select
$("#select_id ").get(0).selectedIndex=1; //Set the item with Select index value to 1 to select
$("#select_id ").val( 4); //Set the value of Select to 4 and select the item
$("#select_id option[text='jQuery']").attr("selected", true); //Set the Text value of Select Select

$("#ddlRegType").find("option:selected").text();

$("#nowamagic").val();

$("#nowamagic").get(0).selectedIndex;

$("#select_id").append("Text"); //Add an Option (drop-down item) to Select
$("#select_id").prepend("Please select"); //Insert an Option for Select (the first position)
$("#select_id option:last").remove(); //Remove the Option with the largest index value in Select (the last one)
$(" #select_id option[index='0']").remove(); //Delete the Option with index value 0 in Select (the first one)
$("#select_id option[value='3']" ).remove(); //Delete Option with Value='3' in Select
$("#select_id option[text='4']").remove(); //Delete Text='4 in Select 'Option

//index is the index value
$("#nowamagic").get(0).selectedIndex=index;

$("#nowamagic").attr("value"," Normal");
$("#nowamagic").val("Normal");
$("#nowamagic").get(0).value = value;

var count=$( "#nowamagicoption").length;
for(var i=0;i{ if($("#nowamagic").get(0).options[i].text = = text)
{
$("#nowamagic").get(0).options[i].selected = true;

break;
}
}

$( "#nowamagic").empty();