Check if a string is an email address in PHP

Question

I am trying to do an SQL query, but I need to check somehow if the value is an email address. I need a way to check if $user is an email address, because I have user values such as this in my table.

test
test2
[email protected]
[email protected]
test392
[email protected]

and so on...

I need to make it so $useremail checks $user to find if it's an email address. So I can UPDATE the values, WHERE user=test OR [email protected], etc.

$user = strtolower($olduser);
$useremail = "";

mysql_query("UPDATE _$setprofile SET user=$sn, fc=$fc WHERE user='$user' OR user='$useremail");

Answer 1

This is not a great method and doesn't check if the email exists but it checks if it looks like an email with the @ and domain extension.

function checkEmail($email) {
   $find1 = strpos($email, '@');
   $find2 = strpos($email, '.');
   return ($find1 !== false && $find2 !== false && $find2 > $find1);
}

$email = '[email protected]';
if ( checkEmail($email) ) {
   echo $email . ' looks like a valid email address.';
}