<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>箭头函数-普通函数</title>
</head>
<body>
<p id="demo"></p>
<script>
let hello;
hello = function () {
return "Hello World!";
}
document.getElementById("demo").innerHTML = hello();
</script>
</body>
</html>