使用正则表达式验证以逗号分隔的单词字符串的格式 [英] Validate the format of a string of comma separated words with regex

问题描述

我正在尝试使用正则表达式从ruby类的文本字段中验证由逗号分隔的单词的字符串.以下内容应有效:

I'm trying to validate a string of comma separated words from a text field in a ruby class using regex. The following should be valid:

word

word, word, word

word,word,word

以下内容无效:

word word word

我认为这会起作用

/([a-z]+){1}(,\s*[a-z]+)*/i

在Rubular上，它似乎是有效的，但是当我按如下所示在类中进行验证时，它接受应该是无效的字符串.

On Rubular, it seems to be valid, but when I validate in my class as follows, it accepts what should be invalid strings.

@tag_regex = /([a-z]+){1}(,\s*[a-z]+)*/i

validates :tags, 
:allow_blank => true,
:format => { :with => @tag_regex, :message => "Invalid tag format." }

我不确定我的问题出在正则表达式还是验证方法本身.感谢您的帮助.

I'm not sure whether my problem lies in the regex or with the method of validation itself. Any help is appreciated.

推荐答案

您忘记使用^(字符串的开头)和$(字符串的结尾)

You forgot to use ^(start of the string) and $(end of the string)

所以应该是

/^([a-z]+)(,\s*[a-z]+)*$/i

---

如果没有^，$，它将在字符串之间的任意位置匹配.使用^，$，您将使其完全匹配

---

Without ^,$ it would match anywhere in between the string..With ^,$ you are making it match exactly

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