Some bizarre manipulations of jquery values

Syntax Explanation:
1. $ ("#select_id"). Change (function () {//code ...}); Add an event for Select, which is triggered when one of the items is selected
2. Var checktext=$ ("#select_id"). Find ("option:selected"). Text (); Gets the text selected by the Select
3. Var checkvalue=$ ("#select_id"). Val (); Gets the value selected by select
4. Var checkindex=$ ("#select_id"). Get (0). SelectedIndex; Gets the index value of the Select selection
5. Var maxindex=$ ("#select_id option:last"). attr ("index"); Gets the maximum index value of the Select
jquery sets the text and value selected for select:
Syntax Explanation:
1. $ ("#select_id"). Get (0). selectedindex=1; Set the Select index value to 1 to select
2. $ ("#select_id"). Val (4); Sets the value of select to 4 for the item selected
3. $ ("#select_id option[text= ' jQuery ']"). attr ("selected", true); Set the text value of select to the item selected for jquery

jquery Add/Remove option for select:
Syntax Explanation:
1. $ ("#select_id"). Append ("<option value= ' value ' >Text</option>"); Append an option to the Select (drop-down item)
2. $ ("#select_id"). Prepend ("<option value= ' 0 ' > Please select </option>"); Insert an option for select (first position)
3. $ ("#select_id option:last"). Remove (); Delete index value in select maximum option (last)
4. $ ("#select_id option[index= ' 0 ']"). Remove (); Delete option with index value 0 in select (first)
5. $ ("#select_id option[value= ' 3 ']"). Remove (); Delete option for value= ' 3 ' in select
5. $ ("#select_id option[text= ' 4 ']"). Remove (); Delete option for text= ' 4 ' in select

jquery Radio value, checkbox value, select Value, Radio selected, CheckBox selected, select selected, and its related
Gets the value of a set of radio selected items
var item = $ (' input[name=items][checked] '). Val ();
Gets the text of the Select selected item
var item = $ ("Select[name=items] option[selected]"). Text ();
The second element of the Select drop-down box is the currently selected value
$ (' #select_id ') [0].selectedindex = 1;
Radio the second element of a radio group is the currently selected value
$ (' input[name=items] '). Get (1). checked = true;
Get Value:
text box, text area: $ ("#txt"). attr ("value");
Multi Box checkbox:$ ("#checkbox_id"). attr ("value");
Radio Group Radio: $ ("input[type=radio][checked]"). Val ();
Drop-down box select: $ (' #sel '). Val ();
Control form elements:
text box, text area: $ ("#txt"). attr ("Value", "");//Clear Contents
$ ("#txt"). attr ("value", ' 11 ');//fill content
Multiple marquee checkbox: $ ("#chk1"). attr ("Checked", "");//No Tick
$ ("#chk2"). attr ("Checked", true);//tick
if ($ ("#chk1"). attr (' checked ') ==undefined)//Determine if a tick has been made
Radio Group Radio: $ ("Input[type=radio]"). attr ("Checked", ' 2 ');//Set value=2 for the currently selected item
Drop-down box select: $ ("#sel"). attr ("value", '-sel3 ');//Set the VALUE=-SEL3 item as the current selection
$ ("<option value= ' 1 ' >1111</option><option value= ' 2 ' >2222</option>"). AppendTo ("#sel")// option to add a drop-down box
$ ("#sel"). empty ();//Empty drop-down box

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Traverse option and Add, remove option
function Changeshipmethod (shipping) {
var len = $ ("select[name=ishiptype] option"). length
if (shipping.value! = "CA") {
$ ("select[name=ishiptype] option"). each (function () {
if ($ (this). val () = = 111) {
$ (this). Remove ();
}
});
}else{
$ ("<option value= ' 111 ' >ups ground</option>"). AppendTo ($ ("Select[name=ishiptype]"));
}
}

Get the selected value of the dropdown

$ (#testSelect option:selected '). Text ();
or $ ("#testSelect"). Find (' option:selected '). Text ();
or $ ("#testSelect"). Val ();
//////////////////////////////////////////////////////////////////
A bad memory can be collected:
1, drop-down box:

var cc1 = $ (". FORMC select[name= ' country '] option[selected]"). Text (); Gets the text of the selected item in the drop-down menu (note that there are spaces in the middle)
var CC2 = $ ('. FORMC select[name= "Country"]). Val (); Get the value of the selected item in the drop-down menu
var cc3 = $ ('. FORMC select[name= "Country"]). attr ("id"); Gets the id attribute value of the selected item in the drop-down menu
$ ("#select"). empty ();//Empty the drop-down box//$ ("#select"). HTML (");
$ ("<option value= ' 1 ' >1111</option>"). AppendTo ("#select")//option to add a drop-down box

A little explanation:
1.select[name= ' country '] option[selected] means having the Name property,
and the option element with the selected attribute in the Select element with the attribute value of ' country ';

2, Radio Box:
$ ("input[@type =radio][@checked]"). Val (); Get the value of the selected item in the Radio box (note that there are no spaces in the middle)
$ ("input[@type =radio][@value =2]"). attr ("Checked", ' checked '); Sets the value=2 of the radio box to the selected state. (note there is no space in the middle)

3, check box:
$ ("input[@type =checkbox][@checked]"). Val (); Gets the value of the check box for the first item selected
$ ("input[@type =checkbox][@checked]"). each (function () {////Because the check box is generally selected as multiple, you can loop the output
Alert (This). Val ());
});

$ ("#chk1"). attr ("Checked", "");//Not ticked
$ ("#chk2"). attr ("Checked", true);//tick
if ($ ("#chk1"). attr (' checked ') ==undefined) {}//Determine if a tick has been made

Of course the jquery selector is powerful. There are many other ways.

<script src= "Jquery-1.2.1.js" type= "Text/javascript" ></script>
<script language= "javascript" type= "Text/javascript" >
$ (document). Ready (function () {
$ ("#selectTest"). Change (function ()
{
Alert ("Hello");
Alert ($ ("#selectTest"). attr ("name"));
$ ("a"). attr ("href", "xx.html");
Window.location.href= "xx.html";
Alert ($ ("#selectTest"). Val ());
Alert ($ ("#selectTest option[@selected]"). text ());
$ ("#selectTest"). attr ("Value", "2");

});
});
</script>

<a href= "#" >aaass</a>

<!--drop-down box--
<select id= "Selecttest" name= "Selecttest" >
<option value= "1" >11</option>
<option value= "2" >22</option>
<option value= "3" >33</option>
<option value= "4" >44</option>
<option value= "5" >55</option>
<option value= "6" >66</option>
</select>
jquery Radio value, checkbox value, select Value, Radio selected, CheckBox selected, select selected, and its related to get a set of radio values of the selected item
var item = $ (' input[@name =items][@checked] '). Val ();
Gets the text of the Select selected item
var item = $ ("select[@name =items] option[@selected]"). Text ();
The second element of the Select drop-down box is the currently selected value
$ (' #select_id ') [0].selectedindex = 1;
Radio the second element of a radio group is the currently selected value
$ (' input[@name =items] '). Get (1). checked = true;
Get Value:
text box, text area: $ ("#txt"). attr ("value");
Multi Box checkbox:$ ("#checkbox_id"). attr ("value");
Radio Group Radio: $ ("input[@type =radio][@checked]"). Val ();
Drop-down box select: $ (' #sel '). Val ();
Control form elements:
text box, text area: $ ("#txt"). attr ("Value", "");//Clear Contents
$ ("#txt"). attr ("value", ' 11 ');//fill content
Multiple marquee checkbox: $ ("#chk1"). attr ("Checked", "");//No Tick
$ ("#chk2"). attr ("Checked", true);//tick
if ($ ("#chk1"). attr (' checked ') ==undefined)//Determine if a tick has been made
Radio Group Radio: $ ("input[@type =radio]"). attr ("Checked", ' 2 ');//Set value=2 for the currently selected item
Drop-down box select: $ ("#sel"). attr ("value", '-sel3 ');//Set the VALUE=-SEL3 item as the current selection
$ ("<optionvalue= ' 1 ' & gt;1111</option><optionvalue= ' 2 ' >2222</option& gt;"). AppendTo ("#sel")//option to add a drop-down box
$ ("#sel"). empty ();//Empty drop-down box

Gets the value of a set of radio selected items
var item = $ (' input[@name =items][@checked] '). Val ();
Gets the text of the Select selected item
var item = $ ("select[@name =items] option[@selected]"). Text ();
The second element of the Select drop-down box is the currently selected value
$ (' #select_id ') [0].selectedindex = 1;
Radio the second element of a radio group is the currently selected value
$ (' input[@name =items] '). Get (1). checked = true;
Get Value:
text box, text area: $ ("#txt"). attr ("value");
Multi Box checkbox:$ ("#checkbox_id"). attr ("value");
Radio Group Radio: $ ("input[@type =radio][@checked]"). Val ();
Drop-down box select: $ (' #sel '). Val ();
Control form elements:
text box, text area: $ ("#txt"). attr ("Value", "");//Clear Contents
$ ("#txt"). attr ("value", ' 11 ');//fill content
Multiple marquee checkbox: $ ("#chk1"). attr ("Checked", "");//No Tick
$ ("#chk2"). attr ("Checked", true);//tick
if ($ ("#chk1"). attr (' checked ') ==undefined)//Determine if a tick has been made
Radio Group Radio: $ ("input[@type =radio]"). attr ("Checked", ' 2 ');//Set value=2 for the currently selected item
Drop-down box select: $ ("#sel"). attr ("value", '-sel3 ');//Set the VALUE=-SEL3 item as the current selection
$ ("<option value= ' 1 ' >1111</option><option value= ' 2 ' >2222</option>"). AppendTo ("#sel")// option to add a drop-down box
$ ("#sel"). empty ();//Empty drop-down box

Some bizarre manipulations of jquery values