我正在尝试从许多不同的电子邮件中获取电子邮件地址，并且我正在尝试使用jQuery选择器来获取这些电子邮件地址。但是，我不断收到消息TypeError: undefined is not a function。
html如下所示：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Activate Your Groupon Account</title>
<link rel="important stylesheet" href="">
<style>div.headerdisplayname {font-weight:bold;}</style>
</head>
<body>
<table border=0 cellspacing=0 cellpadding=0 width="100%" class="header-part1">
<tbody></tbody>
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">Subject: </div>
Activate Your Groupon Account
</td>
</tr>
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">From: </div>
Groupon <notify@r.groupon.com>
</td>
</tr>
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">Date: </div>
10/8/2014 12:25 PM
</td>
</tr>
</table>
<table border=0 cellspacing=0 cellpadding=0 width="100%" class="header-part2">
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">To: </div>
myEmail@gmail.com
</td>
</tr>
</table>
<br>
<div class="moz-text-html" lang="x-unicode">
<html>
<head>
<title>Groupon | Wednesday, October 8, 2014</title>
<meta http-equiv="Content-Type" content="text/html; ">
</head>
<body style="height:100%; margin:0!important; padding:0!important;-webkit-text-size-adjust:none; background:#89B556;">
<img src = "http://www.groupon.com/analytic/track.gif?p=1&utm_domain=gmail.com&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da&utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008" height="1" width="1" />
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; width:100%; background:#89B556;" bgcolor="#89B556" valign="top" align="center">
<tr>
<td style="width:33%;" valign="top"> </td>
<td style="width:33%; padding: 0 25px 40px 25px;" valign="top" align="center">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333;" width="600" align="center">
<tr>
<td style="padding: 0 0 0 10px;" align="left" valign="bottom">
<a href="http://www.groupon.com/?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=header&c=logo&d=index&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da"><img src="http://s3.grouponcdn.com/email/images/global_images/logo_pg_top.png" style="display: block; border: none; color:#fff; font-size:22px; font-weight:bold;" alt="GROUPON" title="GROUPON"></a>
</td>
</tr>
<tr>
<td style="-moz-border-radius: 4px 4px 0 0; -webkit-border-radius: 4px 4px 0 0; border-radius: 4px 4px 0 0; -khtml-border-radius: 4px 4px 0 0; background:#fff; padding: 0 0 0 10px;" align="left" valign="top"><a href="http://www.groupon.com/?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=header&c=logo&d=index&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da"><img src="http://s3.grouponcdn.com/email/images/global_images/logo_pg_bottom.gif" style="display: block; border: none; color:#fff; font-size:22px; font-weight:bold;" alt="" title=""></a></td>
</tr>
<tr>
<td style="background:#fff;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; width:100%;" align="center">
<tr>
<td>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333;">
<tr>
<td style="padding:0 18px 20px 25px;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; width:540px;text-align: left; line-height:18px; font-weight: 100;" width="540">
<tr>
<td style="font-size: 22px; color:#82b548; padding: 20px 0 30px 0; font-weight: bold; line-height:28px;">Thanks for Joining!</td>
</tr>
<tr>
<td style="font-family:arial; font-size:20px; color:#949494; line-height: 26px;">You’re going to love it</td>
</tr>
<tr>
<td style="border-bottom: 1px solid #cfe1bc; font-size: 14px; padding: 20px 40px 20px 0;">Check your inbox every day to discover Groupon deals with huge discounts on tasty meals, relaxing spa days, concerts, 5-star hotels and more.</td>
</tr>
<tr>
<td style="padding: 30px 0 10px 0;">To complete your registration for Groupon, please verify your email.</td>
</tr>
<tr>
<td style="padding: 10px 0 20px 0;">
<table cellpadding="0" cellspacing="0" style='font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333;'>
<tr>
<td height="40" width="185" bgcolor="#f98b62" background="http://s3.grouponcdn.com/email/images/global_buttons/gradient_orange_sm.gif" background-repeat="repeat-x" style="height: 40px; -moz-border-radius: 8px 8px 8px 8px; -webkit-border-radius: 8px 8px 8px 8px; border-radius: 8px 8px 8px 8px; -khtml-border-radius: 8px 8px 8px 8px; border: 1px solid #f55d16; text-align: center;">
<a href="https://www.groupon.com/users/activate/8eceddecb9f30c3384fb2507b0d234805698010c?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=secondary-content-area&c=button&d=verify-account&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="padding:5px 20px 5px 20px; color: #fff; text-shadow: 1px 1px 1px #b2552d; font-size: 18px; text-decoration: none; font-weight: bold; display: block;" target="_blank" title="Verify Account">Verify Account</a>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; border-top: 1px solid #cccccc; text-align:left;">
<tr>
<td style="padding: 15px 40px 15px 40px;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333;">
<tr>
<td><a href="https://www.groupon.com/myprofile?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=secondary-content-area&c=image&d=personalize&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none;"><img src="http://s3.grouponcdn.com/email/images/welcome-email/personalize.gif" style="display: block; border: none;" alt="Personalize your deals" title="Personalize your deals"></a></td>
<td style="padding: 0 0 0 20px;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; font-weight: 100; text-align: left;">
<tr>
<td><a href="https://www.groupon.com/myprofile?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=secondary-content-area&c=text-link&d=personalize&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none; font-weight: bold;">Personalize your deals</a></td>
</tr>
<tr>
<td style="padding: 5px 0 0 0;">Help us get you the best deals by completing your profile.</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; border-top: 1px solid #cccccc; text-align: left;">
<tr>
<td style="padding: 15px 40px 15px 40px;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; text-align:left;">
<tr>
<td><a href="http://www.groupon.com/groupon-promise?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=secondary-content-area&c=image&d=groupon-promise&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none;"><img src="http://s3.grouponcdn.com/email/images/welcome-email/promise.gif" style="display: block; border: none;" alt="We got your back" title="We got your back"></a></td>
<td>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; font-weight: bold; color: #5f8237;">
<tr>
<td>The</td>
</tr>
<tr>
<td>GROUPON</td>
</tr>
<tr>
<td style="padding: 0 30px 25px 0;">Promise</td>
</tr>
</table>
</td>
<td style="padding: 0 0 0 20px;">
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; font-weight:100; text-align:left;">
<tr>
<td><a href="http://www.groupon.com/groupon-promise?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=secondary-content-area&c=text-link&d=groupon-promise&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none; font-weight: bold;">We got your back</a></td>
</tr>
<tr>
<td style="padding: 5px 0 5px 0;">If the experience using your Groupon ever lets you down, we’ll make it right or return your purchase.</td>
</tr>
<tr>
<td>Simple as that.</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; width:600px; border-top: 1px solid #7a9e32; text-align: center; " width="600" background="#ddeacf" bgcolor="#ddeacf" align="center">
<tr>
<td style="padding: 10px 30px 10px 30px; color:#666; font-family: Arial, Helvetica, sans-serif; font-weight: bold;" align="center">
Need help? <span style="color:#0185C6; text-decoration:none;"><a href="https://www.groupon.com/helpcenter?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=contact-block&c=text-link&d=contact-groupon&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none;">Contact Groupon</a></span>
</td>
</tr>
</table>
<table cellpadding="0" cellspacing="0" style="font-family: Arial, Helvetica, sans-serif; font-size:14px; line-height:19px; color:#333; background:#eff5e7; width:600px; -moz-border-radius: 0 0 4px 4px; border-radius: 0 0 4px 4px; -webkit-border-radius: 0 0 4px 4px; -khtml-border-radius: 0 0 4px 4px;" align="center" width="600">
<tr>
<td style="padding: 10px 0 10px 0; font-size: 10px; text-align: center;">Delivered by Groupon Inc. 600 W. Chicago Avenue, Suite 400 Chicago, IL, 60654, USA</td>
</tr>
<tr>
<td style="padding: 0 20px 0 20px; font-size:10px; line-height: 14px; color:#666666; text-align: left;" valign="top">
You are receiving this email because you signed up for the Daily Groupon alerts. If you prefer not to receive the daily Groupon email, you can always <a href="https://www.groupon.com/subscription_center/fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106?mobile=false&utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=footer&c=link&d=subs-center&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none;" target="_blank">manage your subscriptions</a>. Be sure to add us to your address book or safe sender list so our emails get to your inbox. <a href="http://www.groupon.com/pages/whitelist?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=footer&c=link&d=groupon_whitelist&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da" style="color:#0185C6; text-decoration:none;" target="_blank">Learn how</a>
</td>
</tr>
<tr>
<td align="center" style="padding: 20px 0 20px 0;"><a href="http://www.groupon.com?utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008&s=footer&c=logo&d=index&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da"><img src="http://s3.grouponcdn.com/email/images/global_images/footer_pg_ico.gif" style="display: block; border: none;" alt="GROUPON" title="GROUPON"></a></td>
</tr>
</table>
</td>
<td style="width:33%;" valign="top"> </td>
</tr>
</table>
<img src = "http://www.groupon.com/analytic/track.gif?p=2&utm_domain=gmail.com&utm_campaign=55dd4215-7b6d-4818-9a72-0da61a4540da&utm_source=activation_notification&utm_medium=email&sid=55dd4215-7b6d-4818-9a72-0da61a4540da&user=fb4de52d8d1af92fd57e6e895aa7c9a0f846d88bd27c203571f4e3776baa6106&date=20141008" height="1" width="1" />
</body>
</html>
</div>
</body>
</html>
</table></div>
我用来选择它的代码有效：
$('tr:nth-child(2) td')
但是一旦我尝试抓住文本它就会破坏：
$('tr:nth-child(2) td').text()
答案 0 :(得分：0)
由于新要求而修订的答案：
检查这个小提琴：http://jsfiddle.net/2uvk9zxp/ 假设您想要的电子邮件每次都在完全相同的位置，您将不得不抓住某些元素并将其拆分到某些地方。
这是我正在使用的javascript：
var getEmail = $('tr:nth-of-type(2) td').html().split("Groupon ")[1].split(" ")[0].replace("<","").replace(">","");
console.log(getEmail);
END REVISED
问题是您的<tbody>未包含在<table>内。正如Magnus Engdal所说，它是无效的标记，因此javascript无法正确读取。
您所要做的就是将表格包装在实际的<table></table标签中。
这里有一个示例WITHOUT表标签的小提琴： http://jsfiddle.net/h58hvxxk/2/
以下是WITH表标签的示例： http://jsfiddle.net/h58hvxxk/3/
您可以看到提示框工作正常，拉出您要查找的文字。 - 这个功劳归功于马格努斯，所以如果他写下同样的答案，你需要接受并投票给他。 - P.S.不要让我写一个(1)而不是(2)的事实阻止你看到它运作正常。
答案 1 :(得分：0)
我与所有未被TS读取的评论联系在一起。
您的表格结构没有问题。
错误TypeError: undefined is not a function告诉我们
你的jQuery没有加载，js什么都不知道
约$()结构或您在页面上有冲突
另一个js框架（如mootools）。为了解决这个问题
冲突 - 使用jQuery('tr:nth-child(2) td').text()
使用js代码显示页面的完整代码，而不仅仅是其中的一部分。
<notify@r.groupon.com>无法通过.text()函数访问，因为浏览器认为这是一个标记。使用.html()并解析。看这里 - http://jsfiddle.net/u6oa25b5/1/
可以在不解析html代码的情况下这样做。
喜欢这个（此处的电子邮件位于div标记内，仅为了简单起见） - http://jsfiddle.net/u6oa25b5/2/
var email = $('div').find('*').filter(function(){
if (this.tagName.search(/@/) !== -1)
return this;
});
alert(email[0].tagName);
答案 2 :(得分：0)
尝试
HTML
<td>
<div class="headerdisplayname" style="display:inline;">From: </div>
<!-- wrap email address inside `span` tag -->
Groupon <span>notify@r.groupon.com</span>
</td>
JS
// apply rendering of `<` , `>` around email address text in `span`
var email = $("tr:nth-child(2) td span").before("<").after(">").text();
console.log(email)
在<替换文字>，html。如果要将电子邮件地址呈现为实际可导航的链接？ ，换行包裹在a（锚）标记中，然后将a标记的href属性设置为mailto:notify@r.groupon.com
var email = $("tr:nth-child(2) td span").before("<").after(">").css("color", "blue").text();
console.log(email)<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table border=0 cellspacing=0 cellpadding=0 width="100%" class="header-part1">
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">Subject: </div>
Activate Your Groupon Account
</td>
</tr>
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">From: </div>
Groupon <span>notify@r.groupon.com</span>
</td>
</tr>
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">Date: </div>
10/8/2014 12:25 PM
</td>
</tr>
</table>
<table border=0 cellspacing=0 cellpadding=0 width="100%" class="header-part2">
<tr>
<td>
<div class="headerdisplayname" style="display:inline;">To: </div>
myEmail@gmail.com
</td>
</tr>
</table>
答案 3 :(得分：0)
其他所有答案都没有用，这可能是由于此页面上有jQuery的内容。 $选择器有效，但输入jQuery未定义。
这最终有效：
document.querySelectorAll('.headerdisplayname')[1].parentNode.children[1].tagName
或
document.querySelectorAll('tr > td')[1].children[1].tagName