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" onkeydown="value=value.replace(/[^\d]/g,'')"
onkeyup="value=value.replace(/[^\d]/g,'')"
onkeypress="value=value.replace(/[^\d]/g,'')" maxlength="11">
</body>
</html>
3、实现结果
