good idea to use regex for this

if  /[^"]$/ is a regex match this means m// is the operator and  [^"]$ is the regex pattern (the regex )

the / and / are delimiters, they're not part of the regex pattern; you use a regex by using m//atch or s///ubstitute operators

m//atch operator s///ubstitution operator tr///ansliteration operator

to m//atch to s///ubstitute to tr///ansliterate

it sinks in quicker when you realize the regex are arguments top m//atch and s///ubstitute, and tr///ansliterate takes chars/char-ranges not regex

Simple matching, Simple substitution

:)