c# regex for awkward mail and phone number

Question

I've used the following 2 regex, that I have found here:

1. for 10 digit phone number with space before and after it: @"(?<!\\d)\\d{10}(?!\\d)"

2. For email:

 @"(([\\w-]+\\.)+[\\w-]+|([a-zA-Z]{1}|[\\w-]{2,}))@" + @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]? 

[0-9]{1,2}|25[0-5]|2[0-4][0-9])." + @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9]).([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|" + @"([a-zA-Z]+[\\w-]+.)+[a-zA-Z]{2,4})";

the email regex works fine for normal and correct email addresses,

but my input text isn't actually normal and correct, sau I have to introduce another particularity for it, I would also like it to parse:

myname@this -email.com *or* myname@this- email.com *or* myname@this - email.com

And the 10 digit number phone regex only extracts the last 9 digits of the number, with the phone number starting with 0 :

for nr = 0123456789 I only get : 123456789 , the phone number is found in text like: "some text here 0123456789 and some more here" .

I've also found that the 10 digit number may be found in this form : 012/3456789

Answer 1

1. I don't believe you need to use look ahead to match your phone number. You could do something like " (\\d[^0-9a-zA-Z]*?){9}\\d " to match for numbers exactly 10 digits long, with any kind of junk between the numbers (except az letters). Careful though, it would also match stuff like " 012 à 3456789 " . If the single slash is the only possible separator, you can use " (\\d/?){9}\\d " : no false positive but you wont match unexpected separators.

2. Regarding the email matter, the official complete regex is pretty long. Gusdor's link ( http://www.regular-expressions.info/email.html ) gives some context and a simple one that should match pretty much every email address actually in use. Tweaking it a little bit to match your case ( this -domain.com or this- domain.org would be matched), you could use something like this:

    [a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9]*( *?- *)?[a-z0-9]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])? 

The custom part here is the ( *?- *)? added to the right place.