<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
var a;
a = setTimeout(alert("5s"),5000)
</script>
</head>
<body>
</body>
</html>
为什么js中的setTimeout()没有延迟5s弹框,而是直接弹框
