title: convert return object to json but only certain value pairs
body: <p>Yes I know there are heaps of posts about converting objects to json but my question is more specific.. </p>
  
  <p>Say Im calling some data from an api and the response is an object that looks like this</p>
  
  <pre><code>{
      date: ...,
      value: ...,
      useless-info: ...,
      useless-info: ...
  }
  </code></pre>
  
  <p>now I know I can do this <code>JSON.stringify(returnedobject);</code></p>
  
  <p>so I get the newly formed json..</p>
  
  <pre><code>{
     "date": ...,
     "value": ...,
     "useless-info": ...,
     "useless-info": ...
  }
  </code></pre>
  
  <p>now all I want in my newly formed json to be the <code>"date"</code> and <code>"value"</code> and remove the <code>useless-info</code> is this even possible?</p>
  
  <p>any help would be appreciated!</p>