How to list variables declared in script in bash?

Question

In my script in bash, there are lot of variables, and I have to make something to save them to file. My question is how to list all variables declared in my script and get l

Answer 1

Based on some of the above answers, this worked for me:

before=$(set -o posix; set | sort);

source file:

comm -13 <(printf %s "$before") <(set -o posix; set | sort | uniq)