效果：
目录：
index.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<link rel="prefetch" href="index.js" as="script" onload="loadjs()">
</head>
<body onload="load()">
<a href="next.html">下一页</a>
<script>
const loadjs = () => {
console.log('index.js onload')
}
const load = () => {
console.log('body onload')
}
</script>
</body>
</html>
next.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="index.js"></script>
</head>
<body>
下一页了
<script>
let sum = add(1, 2)
console.log(sum)
</script>
</body>
</html>index.js:
console.log('运行')
const add = (a, b) => {
return a + b
}