title: how to take addition in json data
body: <p>I need Addition of <code>qty</code> in <code>+ (sum of qty) +</code>. What do I need to do? </p>
  
  <pre><code>[{"qty": "34"},{"qty": "5"}]
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>$.ajax({
      url: "localhost/sp/text.json", //json link
      dataType: 'json',
      success: function(data) {
          var items = [];
          $.each(data, function(key, val) {
              items.push("&lt;tr&gt;");
              items.push("&lt;td id=''" + key + "''&gt;" + val.qty + &lt; /td&gt;");
              items.push("&lt;td id=''" + key + "''&gt;" + (sum of qty) + &lt; /td&gt;"); //need sum of qty here
              items.push("&lt;/tr&gt;");
          });
      }
  });
  </code></pre>