我们最经常遇到的验证，就是电子邮件地址验证。网站上常见。各种网页脚本也都常用“正则表达式”（regular expression）对我们输入的电子邮件地址进行验证，判断是否合法。有的还能分解出用户名和域名。现在用JavaScript语言实现一下电子邮件地址验证程序，用的是JavaScript语言的正则表达式库。
效果图：
不合法的情况：
合法的情况：
源代码如下，该网页已在IE、Firefox、Chrome上验证通过：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="zh" xml:lang="zh">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<title>电子邮件地址验证程序</title>
<script language="javascript" type="text/javascript">
//<![CDATA[
function check( email_address )
{
var regex = /^([0-9A-Za-z\-_\.]+)@([0-9a-z]+\.[a-z]{2,3}(\.[a-z]{2})?)$/g;
if ( regex.test( email_address ) )
{
var user_name = email_address.replace( regex, "$1" );
var domain_name = email_address.replace( regex, "$2" );
var alert_string = "您输入的电子邮件地址合法\n\n";
alert_string += "用户名：" + user_name + "\n";
alert_string += "域名：" + domain_name;
window.alert( alert_string );
return true;
}
else
{
window.alert( "您输入的电子邮件地址不合法" );
return false;
}
}
//]]>
</script>
</head>
<body style="text-align: center;">
<h1>电子邮件地址验证程序</h1>
请输入电子邮件地址：<input id="email_address" type="text" style="width: 300px;" /><br />
<input type="button" value="验证电子邮件地址" onclick="return check(document.getElementById('email_address').value);" />
</body>
</html>以上就是为大家分享的js正则表达式验证邮件地址，希望对大家的学习有所帮助。
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