<!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>
