title: react hook form - watch vs onchange , which one would be the right approach
body: <p>I am using <code>watch</code>,<code>setValue</code> and <code>getValues</code> to update one dropdown selected value based on another dropdown selected value.
  It can be also done using dropdown list's <code>onChange</code> so, <code>onChange</code>, <code>setValue</code> and <code>getValues</code> so no need to use of <code>watch</code>.
  Can you please guide, <code>watch</code> is performance cost then using <code>onChange</code> or it will be fine with watch how its implemented below (without <code>onChange</code>).</p>
  <pre><code>const dropdownList_1_watch_value = watch(dropdownList_1);
  
      useEffect(()=&gt;{
      if (dropdownList_1_watch_value !== 'specificValue') &amp;&amp; getValues(dropdownListControlName) !== defaultValue)
      {
      setValue(another_dropdownListControlName, defaultValue);
      }},[dropdownList_1_watch_value]);
  
  return (
  &lt;&gt;
   // list of dropdown list components and other controls
  &lt;/&gt;
  
  );
  </code></pre>