add id to jquery code example

Example 1: how to add id in jquery

<h2>Greetings</h2>
<div class="container">
  <div class="inner">
    Hello
    <p>Test</p>
  </div>
  <div class="inner">
    Goodbye
    <p>Test</p>
  </div>
</div>

Example 2: how to add id in jquery

var pdiv = $( "p" );
pdiv.add( "div" ); // WRONG, pdiv will not change