I have a piece of code.

Things i want to do:

1. Remove punctuation from beginning and end.

2. Return empty string if no alphabetic character is found

3. Convert string to lowercase

My code is not working if I input something like: &*&98{}||{. It should return an empty string but returns 98. Can you solve this issue for me?

string cleanToken(string s) { // This for loop will remove any punctuation from the beginning until the first letter is encountered for (int i = 0, len = s.size(); i < len; i++) { if (ispunct(s[i])) { s.erase(i--, 1); len = s.size(); } else { break; } } // This for loop will remove any punctuation from the end until the first letter is encountered for (int i = s.size() - 1; i > 0; i--) { if (ispunct(s[i])) { s.erase(i); } else { break; } } transform(s.begin(), s.end(), s.begin(), ::tolower); // convert string to lowercase

return s; }