title: PrimeNg p-dropdown Does not Display Array Values
body: <p>I have component using PrimeNg p-dropdown.<br>
  html code:  </p>
  
  <pre><code>&lt;p-dropdown [style]="{'width':'150px'}" [options]="portNames" placeholder="Select a Port"&gt;
  &lt;/p-dropdown&gt;
  </code></pre>
  
  <p>ts portNames decleration:</p>
  
  <pre><code>portNames: string[] =["Port 01","Port 02", "Port 03"];
  </code></pre>
  
  <p>My Problem is that DropDown Does not Display Values "Port 01","Port 02", "Port 03".</p>
  
  <p>Maybe I have any mistake?</p>