title: Merge two object a delete difference
body: <p>I want to merge two objects to get one final object. the values of the <code>obj2</code> has to overwrite the values of the <code>obj1</code> but the final object has to have the same keys as the <code>obj1</code> (no more, no less) so the keys of the <code>obj2</code> that don't exist in <code>obj1</code> have to be deleted.
  Here an exemple of what I mean</p>
  <pre><code>const obj1 = {
    name: &quot;Pauline&quot;,
    age:20,
    city:&quot;Paris&quot;
  }
  
  const obj2 = {
    name:&quot;Pauline&quot;,
    age:19,
    country:&quot;France&quot;
  }
  
  const finalObject = {
    nama:&quot;Pauline&quot;,
    age:19,
    city:&quot;Paris&quot;
  }
  </code></pre>
  <p>I would appreciate any help</p>