How can I create a JavaScript regex for finding email addresses in strings?

Question

I have a logic app which is triggered by emails in an inbox. It is all working, except for some emails are getting through when I don't want them. Or rather an email signature with an image description of image001.png@01D766B1.7C184990 is getting through. I think it might be my regex that is allowing it, but I am not very good with regex.

Here is the code I have so far:

 var reg = /([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\\.[a-zA-Z0-9_-]+)/gi; var emailData = " \\n\\n'Phonenumber2@test.com'\\n\\n \\n\\n DevOps\\n[cid:image001.png@01D766B1.7C184990]\\n\\n "; //Matching email signatures var matches = emailData .match(reg); console.log(matches);

I need the regex to return a list of any email addresses, but they need to be fully formed. Unlike the one mentioned above which is missing the .com (or .org etc).

Answer 1

Your regex (allowing everything which has an @ and a . )

 const regex = /([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\\.[a-zA-Z0-9_-]+)/gm; const str = `Phonenumber2@test.com Phonenumber2@test.info image001.png@01D766B1.7C184990 Phonenumber2@test.org`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } console.log(m[0]); }

#1 No numbers allowed after last .

 const regex = /([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\\.[a-zA-Z_-]+)/gm; const str = `Phonenumber2@test.com Phonenumber2@test.info image001.png@01D766B1.7C184990 Phonenumber2@test.org`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } console.log(m[0]); }

#2 Restrict characters after last . to be min 2 and max 7 characters {2,7}$

 const regex = /([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\\.[a-zA-Z0-9_-]{2,7}$)/gm; const str = `Phonenumber2@test.com Phonenumber2@test.info image001.png@01D766B1.7C184990 Phonenumber2@test.org`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } console.log(m[0]); }

#3 Define a list of possible top-level domain names like (com|org|info)

 const regex = /([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\\.(com|org|info)$)/gm; const str = `Phonenumber2@test.com Phonenumber2@test.info image001.png@01D766B1.7C184990 Phonenumber2@test.org`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } console.log(m[0]) }

Answer 2

have a look at - https://ihateregex.io/expr/email/

Hate to break it to you but email match via Regex are hard if not impossible.

one way would be matching things with domain name TDN endings ( you can create a group of all tdn and match or just limit the end part of regex - modified regex and filter it out from there onwards.