All Selector ("*")

all ( ) version added: 1.0

Description: Selects all elements.

Caution: The all, or universal, selector is extremely slow, except when used by itself.

Examples:

Example: Find every element (including head, body, etc) in the document. Note that if your browser has an extension/add-on enabled that inserts a <script> or <link> element into the DOM, that element will be counted as well. 

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>css demo</title>

  <style>

  h3 {
    margin: 0;
  }
  div, span, p {
    width: 80px;
    height: 40px;
    float: left;
    padding: 10px;
    margin: 10px;
    background-color: #EEEEEE;
  }

  </style>

  <script src="//code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
  

<div>DIV</div>
<span>SPAN</span>
<p>P <button>Button</button></p>

<script>

var elementCount = $( "*" ).css( "border", "3px solid red" ).length;
$( "body" ).prepend( "<h3>" + elementCount + " elements found</h3>" );

</script>

  
</body>
</html>

Demo:

Example: Find all elements within document.body so elements like head, script, etc. are excluded. 

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>css demo</title>

  <style>

  h3 {
    margin: 0;
  }
  div, span, p {
    width: 80px;
    height: 40px;
    float: left;
    padding: 10px;
    margin: 10px;
    background-color: #EEEEEE;
  }
  #test {
    width: auto;
    height: auto;
    background-color: transparent;
  }

  </style>

  <script src="//code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
  

<div id="test">
  <div>DIV</div>
  <span>SPAN</span>
  <p>P <button>Button</button></p>
</div>

<script>

var elementCount = $( "#test" ).find( "*" ).css( "border", "3px solid red" ).length;
$( "body" ).prepend( "<h3>" + elementCount + " elements found</h3>" );

</script>

  
</body>
</html>

Demo: