JavaScript - 正则表达式与自定义检查

Question

我正在寻找一种方法来创建一个完美(或接近完美)的方法来检查电子邮件是否有效...

虽然我一直在学习正则表达式的概念和技巧,但我想知道创建一个自定义方法来检查电子邮件是否有效使用for循环和比较检查是否更好.我问这个,因为在查看维基百科对有效和无效电子邮件的解释后,http://en.wikipedia.org/wiki/Email_address,正则表达式可能相当复杂.

例:

for (var i = 0; i < email_str.length; i++) {
  if (email_str[i] === '@') {
    // do something
  } else if (other_check) {
    // do something else
  } else if ...
}

如果任何人知道哪个更快(在处理方面),更高效和/或有效,或者如果有人可以提供我学习的链接,那将非常感激.

谢谢和亲切的问候,

克雷格

Answer 1

试图创建一个完美的方法来检查电子邮件是否有效是没有意义的.这是根据RFC822检查电子邮件地址是否有效的正则表达式.

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这完全是矫枉过正的.在"正常"代码中执行此操作也将很长时间.您无需验证完美的电子邮件地址.您也不必担心速度/效率.这称为过早优化,您不应该这样做.当你应该在你的应用程序/项目本身工作时,你只是在浪费你的时间与这样的小事情.

这是一个很好的正则表达式,你可以使用

\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b

这是一个更好的,将匹配99%的电子邮件

[\w!#$%&'*+/=?^`{|}~-]+(?:\.[\w!#$%&'*+/=?^`{|}~-]+)*@(?:\w(?:[\w-]*\w)?\.)+\w(?:[\w-]*\w)?