title: How to get the length of the json object in Angular 2 template
body: <p>I have a array of json like this. </p>
  
  <pre><code>[
    {
      "variations": {
        "title": {
          "newValue": "test new value1",
          "oldValue": "test old value1"
        }
      }
    },
    {
      "variations": {
        "data": {
          "newValue": "new data",
          "oldValue": "httpold data"
        },
        "length": {
          "newValue": "48",
          "oldValue": "9.00"
        }
      }
    }
  ]
  </code></pre>
  
  <p>from this i want to get the length of the variations in Html and also render and values to view.</p>
  
  <pre><code>&lt;table class="table table-bordered table-hover"&gt;
                          &lt;thead class="table-title"&gt;
                              &lt;tr&gt;
                                  &lt;th class="text-center"&gt;Field count&lt;/th&gt;
                                  &lt;th class="text-center"&gt;Field Name&lt;/th&gt;
                                  &lt;th class="text-center"&gt;Old Value&lt;/th&gt;
                                  &lt;th class="text-center"&gt;New Value&lt;/th&gt;
                              &lt;/tr&gt;
                          &lt;/thead&gt;
                          &lt;tbody *ngFor="let data of datas"&gt;
                              &lt;tr&gt;
                                  &lt;td class="text-left" rowspan="2"&gt;{{data.variations.length}}&lt;/td&gt;
                                  &lt;td class="text-left" rowspan="2"&gt;&lt;/td&gt;
                                  &lt;td class="text-left" rowspan="2"&gt;&lt;/td&gt;
                              &lt;/tr&gt;
                              &lt;tr&gt;
                              &lt;/tr&gt;
                          &lt;/tbody&gt;
                      &lt;/table&gt;
  </code></pre>
  
  <p>In the above code  how can i get the <code>length</code> of <code>variation</code> data. also need to render and show all the new field and old field value to the view.
  can any one please help me</p>