[英]Regular expression + Ruby On Rails
I would like to validate my users, so they can only use az and -
in their username. 我想验证我的用户,因此他们只能在用户名中使用az和
-
。
validates_format_of :username, :with => /[a-z]/
However this rule also allows _
-
and capital letters. 然而,这条规则也允许
_
-
和大写字母。 How do I only allow letters, numbers, _
and -
? 如何只允许使用字母,数字,
_
和-
?
This regex makes sure that the first character is a lowercase letter and the rest are either lowercase letters, numbers, hyphens or underscores. 此正则表达式确保第一个字符是小写字母,其余字符是小写字母,数字,连字符或下划线。
/\A[a-z][a-z0-9_-]+\Z/
If you don't care about the first character, you can use 如果您不关心第一个字符,则可以使用
/\A[a-z0-9_-]+\Z/
If you want to make sure the name is minimum 4 characters long: 如果要确保名称长度至少为4个字符,请执行以下操作:
/\A[a-z][a-z0-9_-]{3,}\Z/
If you want to make sure the length is between 4 and 8 如果要确保长度在4到8之间
/\A[a-z][a-z0-9_-]{3,7}\Z/
If the length should be 6 如果长度应为6
/\A[a-z][a-z0-9_-]{5}\Z/
Your regular expression is not specific enough. 您的正则表达式不够具体。 You're looking for something like:
您正在寻找类似的东西:
:with => /\A[a-z_]+\Z/
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