given a string enclosed in round bracckets code example
Example 1: c# regex to find number between parenthesis
\( # Escaped parenthesis, means "starts with a '(' character"
( # Parentheses in a regex mean "put (capture) the stuff
# in between into the Groups array"
[^)] # Any character that is not a ')' character
* # Zero or more occurrences of the aforementioned "non ')' char"
) # Close the capturing group
\) # "Ends with a ')' character"
Example 2: c# get string in parentheses
string input = "User name (sales)";
string output = input.Split('(', ')')[1];