<!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>
<script>
// 用户输入成绩
var score = Number(prompt('请输入成绩'));
// 进行多分支的条件判断
if (score >= 85) {
alert('优秀');
} else if (score >= 70) {
alert('良好');
} else if (score >= 60) {
alert('及格');
} else {
alert('不及格');
}
</script>
</body>
</html>