限制输入框仅能输入11位数字-优快云博客

1、问题背景

输入框中只能输入11个数字，不能输入其他的字符

2、实现源码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>数字正则表达式</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<style type="text/css">
	   #phonenumber{
	   	   width: 200px;
	   	   font-size: 12px;
	   }
	</style>

  </head>
  
  <body>
     <label>只能输入数字：</label>
     <input type="text" οnkeydοwn="value=value.replace(/[^\d]/g,'')" 
     					οnkeyup="value=value.replace(/[^\d]/g,'')"
     					οnkeypress="value=value.replace(/[^\d]/g,'')" maxlength="11">
  </body>
</html>

3、实现结果