title: Obtain specific value using *ngFor in angular5
body: <p>The json response which I obtain is of the format:</p>
  
  <p>0: { type: "bt", ItemName: " tab1"}</p>
  
  <p>1: { type: "st", ItemName: " tab2 "}</p>
  
  <p>This response I am storing in data2 and then printing the data as shown in code below:</p>
  
  <pre><code>&lt;div class="form-group" &gt;
  &lt;label&gt;Item Name&lt;/label&gt;
  &lt;select class="custom-select"&gt;
  &lt;option *ngFor="let data of data2; let i = index;" value = {{i}} &gt;
                                                      {{data.ItemName}}
  &lt;/option&gt;
  &lt;/select&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>This is fetching all the values of ItemName from data2. </p>
  
  <p>But I want to check the value of type in data2 and then print specific ItemName. 
  So, if I select type as "st" then I only want all the ItemNames belonging to this type to be provided in dropdown.</p>
  
  <p>How can I do this?</p>