javascript中字符类出现乱序 [英] Range out of order in character class in javascript
问题描述
我不知道为什么我的正则表达式不正确:
I don't know why my regex is incorrect:
var domain = "google\.com\.br";
var reEmail = new RegExp("^([A-Za-z0-9_\-\.])+\@" + domain + "$");
我需要这个来验证电子邮件.下面的示例:reEmail.test("contact@google.com.br");
I need this to validate an email. Example below: reEmail.test("contact@google.com.br");
我收到此错误:
角色类出现乱序
推荐答案
由于使用字符串创建RegExp,因此_\-\.
变为_-.
,这是无效范围.
(这是从_
到.
的范围,这是不正确的)
Because you create the RegExp using a String the _\-\.
becomes _-.
and that is the invalid range.
(It is a range from _
to .
and that is not correct)
您需要两次逃脱:
new RegExp("^([A-Za-z0-9_\\-\\.])+@" + domain + "$");
这样,\\
在字符串中成为\
,然后用于在RegExp中转义-
.
That way the \\
becomes a \
in the String and then is used to escape the -
in the RegExp.
如果您通过String创建RegExp,则记录结果总是有帮助的,这样可以查看您是否做对了所有事情:
If you create RegExp by String it is always helpful to log the result so that you see if you did everything right:
例如您的RegExp一部分
e.g. your part of the RegExp
console.log("^([A-Za-z0-9_\-\.])+\@");
导致:
^([A-Za-z0-9_-.])+@
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