效果图：
条形图：
目录结构：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<link href="css/style.css" media="screen" rel="stylesheet" type="text/css"/>
<title>Linechart1</title>
</head>
<body>
<div ></div>
<script src="https://d3js.org/d3.v5.min.js"></script>
<script src="js/index.js"></script>
</body>
</html>