checked check box count

How do I count the number of checked chec开发者_运维问答kboxes in a div?

---

var count = 0;
var inputs = myDiv.getElementsByTagName('input');
for (var i = 0, j = inputs.length; i<j; i++) {
    var input = inputs[i];
    if (input.type && input.type === 'checkbox' && input.checked) {
        count++;
    }
}
return count;

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If you have JQuery on your site you can do it this way (assuming yor div has id='myDiv'):

$("#myDiv input:checkbox:checked").length