Js to obtain the option instance selected by the checkbox check box, jscheckbox

Js to obtain the option instance selected by the checkbox check box, jscheckbox

There are countless instances for javascript to get the checkbox check box.
Js implementation:

Var form = document. getElementById ("form2"); var field = form. elements ["test2"]; var option = Dining. getSelectedOption (form, field); var message = ""; for (var I = 0, len = option. length; I <len; I ++) {message + = "Select id:" + option [I]. id + "\ nSelected name:" + option [I]. name + "\ nSelected value:" + option [I]. value + "\ n";} alert (message);/* obtain the selected option */getSelectedOption: function (selectform, selectionfield) {var result = []; var option = null; for (var I = 0; I <selectionfield. length; I ++) {option = selectionfield [I]; if (option. checked) {result. push (option) ;}www.jbxue.com} return result ;}< form id = 'form2'> <label> sort: </label> <input id = 'aaaaa' type = 'checkbox' name = 'test2' value = '1'> <label for = 'aaaaa'> monthly sales </label> <input id = 'bbbbbb' type = 'checkbox' name = 'test2' value = '2'> <label for = 'bbbbb'> score </label> <input id = 'ccccccc' type = 'checkbox' name = 'test2' value = '3'> <label for = 'ccccc '> discount </label> <br style = 'clear: both '> <label> category: </label> <input id = 'ddddd 'type = 'checkbox' name = 'test2' value = '4'> <label for = 'ddddd'> Business Plan </label> <input id = 'eeeee' type = 'checkbox' name = 'test2' value = '5'> <label for = 'eeeee '> cold dish </label> <input id = 'fffff' type = 'checkbox' name = 'test2' value = '6'> </form> ",

How does js obtain the number of check boxes selected by name = checkbox []?

Var inputs = document. getElementsByName ("cb []");

Var checked_counts = 0;

For (var I = 0; I <inputs. length; I ++ ){
If (inputs [I]. checked ){
Checked_counts ++;
}
}

Alert (checked_counts );

How can I obtain the selected value of the check box from js?

<Input type = "checkbox" id = "box" value = "sss1"/>
<Input type = "checkbox" id = "box" value = "sss2"/>
<Input type = "checkbox" id = "box" value = "sss2"/>
<Input type = "checkbox" id = "box" value = "sss2"/>
<Input type = "checkbox" id = "box" value = "sss2"/>
<Input type = "button" name = "btnOK" value = "OK"/>
<Script for = btnOK event = onclick>
Var value = "";
For (var I = 0; I <box. length; I ++ ){
If (box [I]. checked) {// determine whether the check box is selected
Value = value + box [I]. value + ""; // piece together the values... depending on your needs,
}
}
Alert (value); // output the values of the check boxes you selected
</Script>