JQUERY code to get form form value_jquery

Suppose we have the following page:

.......I won’t write it out here

Let’s look at how to get the various values ​​​​in FORM, etc. etc.;
function get_form_value(){
/*Get the value of TEXT.AREATEXT*/
var textval = $("#text_id").attr("value");//or
var textval = $("#text_id").val();
/*Get the value of the radio button*/
var valradio = $("input[@type=radio][@checked]") .val();
/*Get the value of the checkbox*/
var checkboxval = $("#checkbox_id").attr("value");
/*Get all the items in the drop-down list Value*/
var selectval = $('#select_id').val();
//Get the value in the drop-down list selection, this method works for all drop-down boxes
//This The method works for all drop-down boxes
//If you want to get a certain ID, $('#id>option').each() can

$('select>option') .each(function(){
if($(this).attr('selected')==true)
{
alert($(this).text());
}
})
}
3. Other processing of the form:
//Control form elements:
//Text box, text area:
$("#text_id" ).attr("value",'');//Clear the content
$("#text_id").attr("value",'test');//Fill the content
//Multiple selection boxes checkbox:
$("#chk_id").attr("checked",'');//Unchecked value
$("#chk_id").attr("checked",true);/ /Selected value
if($("#chk_id").attr('checked')==undefined) //Judge whether it has been selected
//Single selection group radio:
$("input [@type=radio]").attr("checked",'10');//Set the radio button with value=10 as the currently selected item
//Drop-down box select:
$("# select_id").attr("value",'test'); //Set the item with value=test as the currently selected item
$("testtest2"). appendTo("#select_id")//Add the option of the drop-down box
$("#select_id").empty();//Clear the drop-down box