title: Angular routerLink w/o "[]"
body: <pre><code>&lt;a [routerLink]="..."/&gt;
  &lt;a routerLink="..."/&gt;
  </code></pre>
  
  <p>I see in the tutorial they've used two types of syntaxes for <strong>routerLink</strong> attribute.</p>
  
  <p>I cannot find any documents which tell the differences between them.</p>