title: How to set Default value as null or 0 to Select drop down Angular 7
body: <p>I have a select drop down code is like this in some cases it is hidden , when the select drop down is hidden i want to send null or 0 instead of empty value when i save the form how to do that.</p>
  
  <pre><code>         &lt;div class="col-md-4" [hidden]="!cpSettlement"&gt;
              &lt;select
              class="form-control"
              name="settlement"
              [(ngModel)]="settlement"
              [required]="cpSettlement &amp;&amp; payTermOptions"
            &gt;
  
              &lt;option [value]="'Net'"&gt;Net&lt;/option&gt;
              &lt;option [value]="'Monthly'"&gt;Monthly&lt;/option&gt;
              &lt;option [value]="'Quarterly'"&gt;Quarterly&lt;/option&gt;
            &lt;/select&gt;
          &lt;/div&gt;
  </code></pre>