用js怎么将div中01的内容提取到span里?就是打开html的,div显示的是01,同时span显示的也是01
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<div>01</div>
<span></span>
</body>
</html>