title: convert certain json objects in an array from string to number
body: <p>I am creating an app with angularjs which receives data from 2 api's and creates a chart with smart-table for cryptocurrency data. </p>
  
  <p>I am currently stuck on trying to sort the data in my table using smart-table beacuse the data i recieve from the JSON is string type ( value, % change , and so on) </p>
  
  <p>Here is an example of the JSON that I want to convert certain objects to string type (value,change,rank...)
  <a href="https://i.stack.imgur.com/VGUiE.png" rel="nofollow noreferrer">json file</a></p>
  
  <p>How can i convert certain objects in my JSON to be numbers instead of string so smart-table sorting will work properly.
  It currently sees all the values as strings and sorts as follows: </p>
  
  <pre><code>9999$
  9$
  889% 
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/ArsPh.png" rel="nofollow noreferrer">picture example</a></p>