I am working with Ruby on Rails validations, and need to validate that a given string does not end with 0000. Could anyone provide me with such a regex please. I tried to build one but I'm not very good with regex.

CodePudding user response：

You could use a negative lookahead here:

^(?!.*0000$).*$

You could also try to match ^.*0000$ from your Ruby code and then retain any inputs which do not match to this pattern.

CodePudding user response：

format also accepts without to check for strings not matching the pattern, e.g.:

validates :string_attr, format: { without: /0000\z/,
                                  message: 'must not end with 0000' }