title: finding undefined or null value from object inside object
body: <p>i would like to push keys inside array if found undefined or null</p>
  
  <pre><code>const obj = {
    name:'ab',
    edu:'av',
    degres:{
      a1:'',
      b1:'1'
    },
    platform:undefined
   }
  </code></pre>
  
  <p>i want an output like </p>
  
  <pre><code>  `['a1','platform']`
  </code></pre>
  
  <p>as the value for a1 and platform were null and undefined</p>
  
  <p>i have treid this solution but it doesnt work</p>
  
  <pre><code> function iterater(obj){
    let blankValues = [];
    Object.keys(obj).map((key) =&gt; {
        if (obj.hasOwnProperty(key) &amp;&amp; (typeof obj[key] === "object")) {
          iterater(obj[key])
        } else {
            if (typeof obj[key] === "undefined" || obj[key] === ''){
              blankValues.push(key);
           }
        }
      })
    return blankValues;
  
  }
  </code></pre>
  
  <p>but this somehow only return ['platform'] only,but the expected output should be ['platform','a1'],i think when running iterater(obj[key]),the value of array (blankValues) gets blank as it doesnt perserve it,but please help me with appropriate logic and structure</p>