jquery get all changed checkboxes

I have a large number of checkboxes on the page each in a separate cell and I need to retrieve all of the checkboxes that have had their value changed since the original.

I am storing the original value in an attribute called "data-original-value" in a span that contains the checkbox, the span was added by asp.net when I added the attribute to the Attributes collection.

void Grid_ItemDataBound(object sender, GridItemEventArgs e)
        {
            var checkBoxControls = e.Item.Controls.All().OfType<CheckBox>();

            foreach (var checkBox in checkBoxControls)
            {
                checkBox.Attributes["data-original-value"] = checkBox.Checked.ToString();
            }
        }

The output html looks something like the following:

<td>
    <span data-original-value="True">
    <i开发者_如何学JAVAnput id="ctl00_MainContent_ControlLandMatrixControl_grid_ctl00_ctl04_ctl01" type="checkbox"   checked="checked" name="ctl00$MainContent$ControlLandMatrixControl$grid$ctl00$ctl04$ctl01">
    </span> 
</td>

I am using the following JQuery code to try and identify all of the checkbvoxes that have changed but it seems to be returning all checkboxes even those that haven't changed.

var checkBoxes = $(":checkbox").filter(function () { return $(this).checked != $(this).parent().attr("data-original-value"); });

I believe I am missing something with the comparison but I'm not entirely sure javascript/jquery isnt my fortay.

You don't need to re-invent the wheel, there is a predefined property defaultChecked for checkboxes, compare it with the checked-property.

$(':checkbox').filter(function () 
                      { 
                         return ($(this).prop('checked') 
                                    !=
                                 $(this).prop('defaultChecked')); 
                      });

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Please note: in jQuery <1.6 use this.checked != this.defaultChecked , it will not work using $.attr()

you are comparing a string to a bool, convert the string to a bool using something like

var myBool = Boolean("false"); // == true

var myBool = !!"false"; // == true

You are comparing checkbox checked value which is a boolean against a string value which is True so the filter will not return anything. Try this

var checkBoxes = $(":checkbox").filter(function () { 
      return $(this).checked.toString() != $(this).parent().attr("data-original-value").toLowerCase(); 
});

This might help.... 

var inputs = document.getElementsByTagName("input"); //or document.forms[0].elements;  
 var cbs = []; //will contain all checkboxes  
 var checked = []; //will contain all checked checkboxes  
 for (var i = 0; i < inputs.length; i++) {  
 if (inputs[i].type == "checkbox") {  
   cbs.push(inputs[i]);  
   if (inputs[i].checked) {  
     checked.push(inputs[i]);  
   }  
 }  
}  
var nbCbs = cbs.length; //number of checkboxes  
var nbChecked = checked.length; //number of checked checkboxes