源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>开源教程(ossoft.cn)</title> </head> <body> <p>不管输入是否正确，输入框都会再输入后清空。</p> <p>请输入 5 ~ 10 之间的数字：</p> <input id="demo" type="text"> <button type="button" onclick="myFunction()">点我</button> <p id="p01"></p> <script> function myFunction() { var message, x; message = document.getElementById("p01"); message.innerHTML = ""; x = document.getElementById("demo").value; try { if(x == "") throw "值是空的"; if(isNaN(x)) throw "值不是一个数字"; x = Number(x); if(x > 10) throw "太大"; if(x < 5) throw "太小"; } catch(err) { message.innerHTML = "错误: " + err + "."; } finally { document.getElementById("demo").value = ""; } } </script> </body> </html>
运行结果