title: Does calling functions in templates cause performance issues in Angular2+?
body: <p>I'm still getting used to Angular's change detection implementation, and I'm not clear on whether calling functions in templates causes performance issues.</p>
  
  <p>For example, is it worse to do the following:</p>
  
  <pre><code>&lt;mat-tab-group&gt;
    &lt;mat-tab label="First"&gt; {{ getFirstTab() }} &lt;/mat-tab&gt;
    &lt;mat-tab label="Second"&gt; {{ getSecondTab() }} &lt;/mat-tab&gt;
  &lt;/mat-tab-group&gt;
  </code></pre>
  
  <p>than do:</p>
  
  <pre><code>&lt;mat-tab-group&gt;
    &lt;mat-tab label="First"&gt; {{ firstTabContent }}&lt;/mat-tab&gt;
    &lt;mat-tab label="Second"&gt; {{ secondTabContent }}&lt;/mat-tab&gt;
  &lt;/mat-tab-group&gt;
  </code></pre>
  
  <p>What about:</p>
  
  <pre><code>&lt;button *ngIf="shouldShowButton()" .... &gt;   
  </code></pre>