title: AngularJS: is $$hashkey a reliable key
body: <h2>Question</h2>
  
  <p>I'm interested in the properties of <code>$$hashkey</code> on angular arrays/objects.  </p>
  
  <ol>
  <li>Would each generated hashkey be the same each time you reload a
  page;   a quick test tells me yes but I somewhat assumed it
  wouldn't?</li>
  <li>If you updated/added to the existing array, would the old hashkey's
  stay consistent?</li>
  <li>If the above is true, is there a way to fetch from an array using
  the hashkey? - of cause I could roll my own but before I recreate the wheel I thought I'd ask. </li>
  </ol>
  
  <h2>Example:</h2>
  
  <p>Views would include:  </p>
  
  <ul>
  <li>form data (example has 1 form)</li>
  <li>element data (example has 2 elements)</li>
  <li>element options data (example has 2 options per element)</li>
  </ul>
  
  <p>Fetch method:  </p>
  
  <pre><code>angular.get($$hashkey);
  </code></pre>
  
  <p>You would then pass the hashkey of the element and it would return a reference to that array inside the full array.</p>
  
  <p>Lastly the data would be: </p>
  
  <pre><code>{
      form_id: 1
      form_desc: 'xxx',
      form_name: 'name 1',
      Elements: [
          {
              element_id: 1,
              element_name: 'element1',
              default_value: null,
              disabled: "0",
              element_type: "image",
              ElementOptions: [
                  {
                      show: false,
                      sort_order: 0,
                      value: "ar",
                  },
                  {
                      show: true,
                      sort_order: 1,
                      value: "rw",
                  }
              ],
          },
          {
              element_id: 2,
              element_name: 'element2',
              default_value: null,
              disabled: "0",
              element_type: "image",
              ElementOptions: [
                  {
                      show: false,
                      sort_order: 0,
                      value: "ar",
                  },
                  {
                      show: true,
                      sort_order: 1,
                      value: "rw",
                  }
              ],
          }
      ]
  }
  </code></pre>