title: What is the difference between ng-click="check=true" and ng-click="alterCheck()"
body: <p>I use Angular in my project, but I encounter a problem.<br>
  When I use <code>ng-click="check=true"</code>, after submitting the form, the <code>div</code> still shows, not hides as I expected; while using <code>ng-click="alterCheck()"</code> or adding <code>check=true</code> to the <code>ng-submit</code> expression can fix this problem. So what is the potential reason for this problem?</p>
  
  <pre><code>&lt;div ng-show="check &amp;&amp; form.$invalid"&gt;&lt;/div&gt;
  &lt;!-- &lt;form name="form" ng-submit="check=true &amp;&amp; init()"&gt; --&gt;
  &lt;form name="form" ng-submit="init()"&gt;
      &lt;input type="text" ng-model="text" required/&gt;
      &lt;!--     &lt;input type="submit" ng-click="alterCheck()"/&gt; --&gt;
      &lt;input type="submit" ng-click="check=true"/&gt;
  &lt;/form&gt;
  </code></pre>