title: knockout string comparison in if data-binding
body: <p>The <code>category</code> variable is defined as <code>ko.observable()</code> and child value should be changed according to <code>category</code> value.<br>
  Below if statement always returns false.</p>
  
  <pre><code>&lt;!-- ko if: $parent.category == "Electronics"--&gt;
     &lt;div&gt;abc&lt;/div&gt;
  &lt;!--/ko--&gt;
  </code></pre>
  
  <p>the if satement below also always returns false:</p>
  
  <pre><code>&lt;span data-bind="if: $parent.category == 'Electronics'"&gt;
     &lt;div&gt;abc&lt;/div&gt;
  &lt;/span&gt;
  </code></pre>
  
  <p>How to do comparison in data-binding with hard-code values?</p>