I want to capture all the username that starts with @ symbol and also there is no character before it.
Until now I have a regular expression that could get all the usernames but it also fetches the usernames that have characters before it but i want to ignore them.
/@[\w\d]+/g
分享 You can use a positive look behind to verify that the @ is preceded by space or start of the string.
(?<= |^)@[\w\d]+
(?<= |^) Positive look behind. Ensures that @ is preceded by ^ start of the string. Not the look aheads, doesn't consume any characters, it just checks.Example
$string = "My name is @john_doe from test@test.com";
preg_match("/(?<= |^)@[\w\d]+/", $string, $matches);
print_r($matches);
// Array (
// [0] => @john_doe
// )
