To the actual application of jquery, determine whether the Radio,selelct,checkbox is selected and selected values

jquery take radio radio button values

$ ("Input[name= ' Items ']:checked"). Val ();
Another: Determine if Radio is selected and gets the selected value

As shown below:
function Checkradio () {
var item = $ (": radio:checked");
var len=item.length;
if (len>0) {
Alert ("yes--selected value is:" +$ (": radio:checked"). Val ());
}
}




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



Just started to touch jquery, a lot of things are unfamiliar

When you use $ ("#id") to get the input element of the page, you find $ ("#id"). Value cannot be obtained



Then finally, with the help of the great Baidu, I found the reason for the problem:

$ ("") is a jquery object, not a DOM element



Value is a property of the DOM element



jquery corresponds to the Val


Val (): Gets the current value of the first matching element.



Val (val): Sets the value of each matching element.



So the code should write this:


Value: val = $ ("#id") [0].value;
Assignment: $ ("#id") [0].value = "New value";

or $ ("#id"). Val ("new value");



Or it can be: val = $ ("#id"). attr ("value");



Each of the jquery is very useful, and it replaces JavaScript's for loop

For example, in a function that has a each, in which a condition is set, the function returns True or FALSE.

function MethodOne () {
....
$.each (Array,function () {
if (condition established) {
return true;
}
});
....
}

It turns out that it's always wrong.

After finding the data, it was found that break and continue could not be used within each code block, and that to implement the function of break and continue, the other way
Break----with return false;
Continue--with return ture;

So when I want to use return true to return this function in each, I just let each continue
Even if each is not interrupted, the function cannot return.

Another: Determine if Radio is selected and gets the selected value

As shown below:
function Checkradio () {
var item = $ (": radio:checked");
var len=item.length;
if (len>0) {
Alert ("yes--selected value is:" +$ (": radio:checked"). Val ());
}
}

To the actual application of jquery, determine whether the Radio,selelct,checkbox is selected and selected values