title: Select default option value from typescript angular 6
body: <p>I have a select html like this:</p>
  
  <pre><code>&lt;select ng-model='nrSelect' class='form-control'&gt;                                                                
      &lt;option value='47'&gt;47&lt;/option&gt;
      &lt;option value='46'&gt;46&lt;/option&gt;
      &lt;option value='45'&gt;45&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>How can I select the default value from typescript for example 47 ?</p>