I want to implement the virtual element like
<!-- ko if: $index() > 9 && $index() < 20 -->
but it does not executed. Please help me for it.
Check this out: http://jsfiddle.net/y3KV2/
What you had there works, but it might be that you are missing something else, so I made this little small simple example so you can see how it works.
<div data-bind="foreach: data">
<!-- ko if: $index() > 9 && $index() < 20 -->
test <span data-bind="text: $index()"></span>
<!-- /ko -->
</div>
var vm = function () {
var self = this;
self.data = ko.observableArray([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]);
}
var s = new vm();
ko.applyBindings(s);