howto 在线编辑器 | howto代码测试

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>body {font-family: "Lato", sans-serif;}

.tablink {
  background-color: #555;
  color: white;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  font-size: 17px;
  width: 25%;
}

.tablink:hover {
  background-color: #777;
}

/* 标签内容的样式 */
.tabcontent {
  color: white;
  display: none;
  padding: 50px;
  text-align: center;
}

#London {background-color:red;}
#Paris {background-color:green;}
#Tokyo {background-color:blue;}
#Oslo {background-color:orange;}
</style>
</head>
<body>

<p>单击选项卡式菜单内的按钮：</p>

<div id="London" class="tabcontent">
  <h1>伦敦</h1>
  <p>伦敦是英格兰的首都。</p>
</div>

<div id="巴黎" class="tabcontent">
  <h1>巴黎</h1>
  <p>巴黎是法国的首都。</p> 
</div>

<div id="Tokyo" class="tabcontent">
  <h1>东京</h1>
  <p>东京是日本的首都。</p>
</div>

<div id="Oslo" class="tabcontent">
  <h1>Oslo</h1>
  <p>Oslo is the capital of Norway.</p>
</div>

}
// 获取 id="defaultOpen" 的元素并点击它
document.getElementById("defaultOpen").click();
</script>
   
</body>
</html>

报个问题: