How to check if a string contains a email?

Question

I have this code that checks if an email is valid:

$email = "abc123@sdsd.com"; 
$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/'; 
if (preg_match($regex, $email)) {
 echo $email . " is a valid email. We can accept it.";
} else { 
 echo $email . " is an invalid email. Please try again.";
}

assuming that I have the following string below:

<html>
<body>
<p>abc123@sdsd.com</p>
</body>
</html>

How could I check if that string has an email or not? (since it does not work with the above code)

like chris85 said; doing like this: https://regex101.com/r/jC1tU9/1 — Lucas Reppe Welander, Aug 05 '16 at 21:54

score 6 · Accepted Answer · answered Aug 05 '16 at 21:52

The ^ and $ are anchors, requiring the full string match. If you take that off it will match an email somewhere in the string.

Regex Demo: https://regex101.com/r/xI0bC2/1

PHP Usage (with updated to store found email):

<?php
$email = "<html>
<body>
<p>abc123@sdsd.com</p>
</body>
</html>"; 
$regex = '/[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})/'; 
if (preg_match($regex, $email, $email_is)) {
 echo $email_is[0] . " is a valid email. We can accept it.";
} else { 
 echo $email . " is an invalid email. Please try again.";
}

PHP Demo: https://eval.in/618679

what is $email_is variable containing of ? @chris85 ? – gumuruh Apr 01 '23 at 23:17 — gumuruh, Apr 01 '23 at 23:17

score 2 · Answer 2 · answered Aug 05 '16 at 21:58

There isn't real solution to this problem, since you will easily obtain false positive.

First thing, your pattern is too naive and doesn't match many email addresses that are correct. However a pattern that matches all email addresses doesn't really exist (or is too complicated and inefficient).

A compromise is to select all text nodes that contains a @ using XPath. Then you split each text node on white-spaces and you test each part with the build-in email validation PHP function: filter_var ($part, FILTER_VALIDATE_EMAIL)

How to check if a string contains a email?

2 Answers2

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