HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>.pushStack name args</title>
  <style>
    body { font-family: sans-serif; padding: 16px; max-width: 420px; }
    li { padding: 6px 0; }
    li.picked { color: #b45309; font-weight: 700; }
    button { margin-top: 12px; padding: 8px 14px; }
    #status { margin-top: 10px; color: #64748b; }
  </style>
</head>
<body>
  <ul>
    <li>Alpha</li>
    <li>Bravo</li>
    <li>Charlie</li>
    <li>Delta</li>
  </ul>
  <button type="button" id="go">takeFirst(2)</button>
  <div id="status"></div>
  <script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
  <script>
    $.fn.takeFirst = function ( n ) {
      var els = this.get().slice( 0, n );
      return this.pushStack( els, "takeFirst", [ n ] );
    };
    $( "#go" ).on( "click", function () {
      $( "li" ).removeClass( "picked" );
      var $after = $( "li" ).takeFirst( 2 ).addClass( "picked" ).end();
      $( "#status" ).text( "After .end(), collection length = " + $after.length );
    });
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

jQuery .pushStack() — name and arguments (Try It)