title: active button after check one or more checkbox in Angularjs
body: <p>I have some checkbox, and a button. Now, I want active button when one or more checkbox is checked. How can I do this in angularjs?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"&gt;&lt;/script&gt;
  
  &lt;label&gt;&lt;input type="checkbox" name="check"&gt; First&lt;/label&gt;
  &lt;label&gt;&lt;input type="checkbox" name="check"&gt; Second&lt;/label&gt;
  &lt;label&gt;&lt;input type="checkbox" name="check"&gt; Third&lt;/label&gt;
  
  
  &lt;br&gt;
  &lt;button type="button" disabled ng-model="$scope.btn"&gt;active/deactive&lt;/button&gt;</code></pre>
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  </div>
  </p>