<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<script src="https://cdn.jsdelivr.net/npm/echarts/dist/echarts.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/echarts/map/js/china.js"></script>
</head>
<body>
<div>Hello World</div>
<div id="map" style="width: 600px; height: 400px"></div>
</body>
</html>
src 会将内容嵌入到网页中，替换 script 标签的内容，如果 script 标签加载 js 脚本，资源是国外的，少说也要十多秒钟加载时间，而在此期间浏览器页面是空白的，不会显示任何内容。因此，一般是在 html 底部加载 js 脚本。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
</head>
<body>
<div>Hello World</div>
<script src="https://cdn.jsdelivr.net/npm/echarts/dist/echarts.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/echarts/map/js/china.js"></script>
</body>
</html>