title: Knockout checkedValue
body: <p>I've got a question regarding checkedValue of checked binding in Knockout (<a href="http://knockoutjs.com/documentation/checked-binding.html" rel="nofollow noreferrer">http://knockoutjs.com/documentation/checked-binding.html</a>)</p>
  
  <p>Basically, look this fiddle <a href="http://jsfiddle.net/jo9dfykt/1/" rel="nofollow noreferrer">http://jsfiddle.net/jo9dfykt/1/</a>.
  Why if I click the button "Add Item" the right choise is selected but if I click the second button "Add Item Two" this not succed?
  What are the differences between addItem and addItem2 method in viewModel?</p>
  
  <p>And then, why the  with selectedValue shows nothing?</p>
  
  <p>My goal is to bind a list of radio button to an observableArray and save the entire object into an observable. But I want to set the inital value of radio button without search it on observableArray.</p>
  
  <p><strong>Javascript</strong></p>
  
  <pre><code>var viewModel = {
      items: ko.observableArray([
          { itemName: 'Choice 1' },
          { itemName: 'Choice 2' }
      ]),
      chosenItem: ko.observable(),
      addItem: function() {
                  this.chosenItem(this.items()[0]);
      },
      addItem2: function() {
                  this.chosenItem({itemName: 'Choice 2'});
      }
  };
  viewModel.chosenItem.subscribe(function(newValue){
          console.log(newValue.itemName);
      }),   
  ko.applyBindings(viewModel);
  </code></pre>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;!-- ko foreach: items --&gt;
  &lt;input type="radio" data-bind="checkedValue: $data, checked: $root.chosenItem" /&gt;
  &lt;span data-bind="text: itemName"&gt;&lt;/span&gt;
  &lt;!-- /ko --&gt;
  &lt;input type="button" data-bind="click: addItem" value="Add Item"/&gt;
  &lt;input type="button" data-bind="click: addItem2" value="Add Item Two"/&gt;
  &lt;div&gt;Selected Value: &lt;span data-bind="text: chosenItem.itemName"&gt;&lt;/span&gt;&lt;/div&gt;
  </code></pre>