Question

I have this regex: /\*([^<|\n|\r]+)/

which matches all characters in a string starting with a * and ending in a new line or a ‘<‘, how can I modify this regex to not match strings if they start with a ** (so it will not match if the second character is also a *)

Answer 1

What you need is negative lookarounds.

/(?<!\*)\*(?!\*)([^<\n\r]+)/

Also, [^<|\n|\r] doesn’t do what you think it does. It will match anything that isn’t <, \n, \r, or a literal | character. You don’t need the | inside a character class unless you want to match a literal |.