title: How do i concatenate the ngFor index variable with a hash symbol?
body: <p>I am building an FAQ section that populates the FAQ via an ngFor loop and an FAQ item component. I want to be able to link to positions within the page using the anchor tag. For this i've downloaded the scrollTo module from npmjs. <a href="https://www.npmjs.com/package/ng2-scroll-to" rel="nofollow noreferrer">https://www.npmjs.com/package/ng2-scroll-to</a></p>
  
  <p>This scrollTo module takes a href argument and i'm trying to concatenate the # and the index counter variable of ngFor within a template expression, but when i do this i get an error. Heres my code.</p>
  
  <pre><code>&lt;section id="top"&gt;
    &lt;ol&gt;
      &lt;li *ngFor="let item of faqItems; let i=index" scrollTo href={{"#" + i}}&gt;{{item.question}}&lt;/li&gt;
    &lt;/ol&gt;
  &lt;dl&gt;
    &lt;app-faq-item *ngFor="let item of faqItems; let i=index" 
    [question]="item.question" [answer]="item.answer" [attr.id]="i"&gt;&lt;/app-faq-item&gt;
  &lt;/dl&gt;
  &lt;button scrollTo scrollableElementSelector="#top" scrollYTarget="0"&gt;Go top&lt;/button&gt;
  &lt;/section&gt;
  </code></pre>
  
  <p>The error comes from the href part. Anyone have an idea how to join the i variable and the hashsymbol into one string?</p>