Knockout.js Performance Gotcha #1

http://www.knockmeout.net/2012/03/knockoutjs-performance-gotcha-1ifwith.html

by uedatakuya

HTML

<!-- ko if: items().length > 0 -->
<ol data-bind="foreach: items">
    <li><span data-bind="text:$data"></span></li>
</ol>
<!-- /ko -->

JavaScript

function ViewModel(num) {
    var _items = [];
    for (var i = 0; i < num; i++) {
        _items.push("item"+(i+1));
    }
    this.items = ko.observableArray(_items);    
}

var vm = new ViewModel(10);
ko.applyBindings(vm);