JQuery - is at least one checkbox checked

Question

I am in the process of learning JQuery thanks mostly to the positive reference here on Stack Overflow. I need a function that checks all the checkboxes in an element which h

Answer 1

A radio button list was not an option due to the page layout. I solved it with a Custom Validator.

Add this JavaScript function to the page

function ValidateDDA(s, a) {
    a.IsValid = ($(".chk:checked", $('parentDiv')).length > 0);
}

Then add a CustomValidator to the page

<asp:CustomValidator runat="server" ID="cvDDLCorrect" ClientValidationFunction="ValidateDDA"
ErrorMessage="No hay resuesta correcta" CssClass="error" />

Works like a charm. Thanks for suggestions.

Answer 2

To check if at least one is checked:

 $(".classname:checked", container).length > 0

"container" is the (optional) container element.

If you want to avoid using class names for grouping, you should simply give each checkbox the same name:

<input type="checkbox" name="group1" value="1" />
<input type="checkbox" name="group1" value="2" />
<input type="checkbox" name="group1" value="3" />

Then you can change the test code to:

 $("[name=group1]:checked").length > 0