title: For loop to put the data in array
body: <p>I have the following JSON :</p>
  
  <pre><code>{
   a : 10,
   b : 20,
   c : 30
  }
  </code></pre>
  
  <p>I want the data in following array</p>
  
  <pre><code>var label =['a','b','c']
  var value = ['10','20','30']
  </code></pre>
  
  <p>How can I achieve the same in TypeScript?</p>