<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> <script> var txt=""; function message(){ try { adddlert("Welcome guest!"); } catch(err) { txt="本页有一个错误。 "; txt+="错误描述：" + err.message + " "; txt+="点击确定继续。 "; alert(txt); } } </script> </head> <body> <input type="button" value="查看消息" onclick="message()" /> </body> </html>
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</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>
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> </head> <body> <p>请输出一个 5 到 10 之间的数字:</p> <input id="demo" type="text"> <button type="button" onclick="myFunction()">测试输入</button> <p id="message"></p> <script> function myFunction() { var message, x; message = document.getElementById("message"); message.innerHTML = ""; x = document.getElementById("demo").value; try { if(x == "") throw "值为空"; if(isNaN(x)) throw "不是数字"; x = Number(x); if(x < 5) throw "太小"; if(x > 10) throw "太大"; } catch(err) { message.innerHTML = "错误: " + err; } } </script> </body> </html>
