Correct spelling at the beginning and end?

Question

PHP

Correct spelling at the beginning and end? /^ +$/
php.net/manual/ru/regexp.reference.meta.php But it's not particularly clear.
Here is my regex, only allows from a to z.
preg_match("/^[a-z]+$/", $a)

Answer 1

That's right, but if there is a $ symbol inside az, then you do preg_match("/^[a-z\$]+$/", $a)everything tip-top