通配符选择器

选择所有元素.

jQuery("*")

警告：除非被它自己使用，否则*选择器或通用选择器，其速度是极其慢的。

例子

查找文档中的每一个元素（包括 head, body 等）。 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>
<head>
  <style>
  h3 { margin: 0; }
  div,span,p {
    width: 80px;
    height: 40px;
    float:left;
    padding: 10px;
    margin: 10px;
    background-color: #EEEEEE;
  }
  </style>
  <script src="https://www.lanmper.cn/static/js/jquery-3.5.0.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>

查找document.body的所有元素所以像head，script等元素被排除在外。

<!DOCTYPE html>
<html>
<head>
  <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="https://www.lanmper.cn/static/js/jquery-3.5.0.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>