What is the meaning of the s and m flags in regular expressions?

Question

PHP

Let's take for example a regular expression for one letter n without flags /n/g https://regex101.com/r/3nEjdB/1 as a result, he sees the letters n both in the first and second lines.
What is the point then if I put s - single line nothing will change like m - multiline, because even now without m it perceives the line as multiline.

Answer 1

m changes the behavior of the anchors (^ and $) and s changes the behavior of the dot (.)
Your regex doesn't use (.) , (^) and ($) so you don't see the difference when adding m and s