Validate email address for particular suffix using regex in Ruby-on-Rails

Question

I want to validate email address with a particular suffix which should be like email. It must have .edu or must have @mypost.com. As an example, I have four email addresses as shown below:

1) john@learn.edu - valid

2) john@mypost.com - valid

3) john@gmail.com - invalid

4) john@dblist.org - invalid

I have tried to solve the problem using the below code in my user.rb model file but to no avail.

if ('xc@dblist.com' =~ /\A[\w]([^@\s,;]+)@((mypost|[\w-]+\.)+(edu|com))\z/i) != nil
  return true
else
  return false
end

the conditional is not needed `=~` will either return `nil` or a `Fixnum`. `nil` is a falsey value and `Fixnum` will be a truthy value so the if statement becomes redundant. [Docs](http://ruby-doc.org/core-2.2.0/String.html#method-i-3D-7E) — engineersmnky, Jul 23 '15 at 13:22

score 1 · Accepted Answer · answered Jul 23 '15 at 13:00

1

You can use this regex:

\A\w([^@\s,;]+)@(mypost\.com|[\w-]+\.edu)\z

See demo (I use ^/$ for demo in multilingual mode there)

The (mypost\.com|[\w-]+\.edu) part matches any .EDU domain and MYPOST.COM.

Note that if you do not use captured groups, just use \A\w[^@\s,;]+@(?:mypost\.com|[\w-]+\.edu)\z.

answered Jul 23 '15 at 13:00

Wiktor Stribiżew

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Sorry stribizhev, but i don't know how i can use this in my `if` condition and i have edit my question. Thank you for answer. – rick Jul 23 '15 at 13:23
Please check this [SO post](http://stackoverflow.com/a/4849241/3832970), perhaps it has some hints on what is wrong. In Ruby, [your code and my regex work OK](http://ideone.com/rCENu6). – Wiktor Stribiżew Jul 23 '15 at 13:30

vks · Answer 2 · 2015-07-23T13:03:53.563

1

\A\w([^@\s,;]+)@(?:([\w-]+\.)+edu|mypost\.com)\z

Try this.See demo.

https://regex101.com/r/oC5rY5/2

edited Jul 23 '15 at 13:03

answered Jul 23 '15 at 13:02

vks

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@stribizhev with multiline this would work then wth anchors `^$~ – vks Jul 23 '15 at 13:06
@rick the answer u accepted will not accept `john@learn.sdasd.edu` .do you want to match it ? – vks Jul 23 '15 at 17:37

score 1 · Answer 3 · answered Jul 23 '15 at 13:15

Here is a fairly simple one that seems to meet your rules:

^[\w\-\.]+@(?:(?:[\w\.\-]+\.edu|mypost\.com))$

Example

this part [^@\s;,] is not needed since \w will not capture these anyway.

Note: regex101.com is a great resource for understanding your regex. Example of your regex Explanation is on the right. I think with will help you understand why yours is not working.

Validate email address for particular suffix using regex in Ruby-on-Rails

3 Answers3