【前端】【JavaScript】通过成绩判断等级

image

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<label for="num">成绩：</label><input type="number" placeholder="请输入数字" id="num">
<input type="button" onclick="check()" value="检查">
<p id="result"></p>
<script>
function  check() {
  //结果输出标签
    result = document.getElementById("result")
  //控件方式输入
    let num = document.getElementById("num").value;
    if (num === undefined || num === "") {
        //弹窗方式输入
        num = prompt("输入数字");
    }
  if (num===""){
    alert("请输入0-100的茄子。")
    return false;
  }
  if(num>100 || num<0){
    alert("非法数字，请输入1-100的茄子。")
    return false;
  }
  switch (parseInt(num / 10)) {
    case 10:
    case 9:
      alert("优秀");
      result.innerHTML="<font color='blue'>优秀</font>"
      break;
    case 8:
      alert("良好");
      result.innerHTML="<font color='#8a2be2'>良好</font>"
      break;
    case 7:
      alert("中等");
      result.innerHTML="<font color='#9acd32'>中等</font>"
      break;
    case 6:
      alert("及格");
      result.innerHTML="<font color='yellow'>及格</font>"
      break;
    case 5:
    case 4:
    case 3:
    case 2:
    case 1:
    case 0:
      alert("不及格");
      result.innerHTML="<font color='red'>不及格</font>"
      break;
    default:
      alert("不合法的数字");
  }
}
</script>
</body>
</html>
posted @ 2022-10-14 11:14  萌狼蓝天  阅读(58)  评论(0)  编辑  收藏  举报