C++ Remove punctuation from String

Question

I got a string and I want to remove all the punctuations from it. How do I do that? I did some research and found that people use the ispunct() function (I tried that), but

Answer 1

Another way you could do this would be as follows:

#include  //needed for ispunct()
string onlyLetters(string str){
    string retStr = "";

    for(int i = 0; i < str.length(); i++){
        if(!ispunct(str[i])){
            retStr += str[i];
        }
    }
    return retStr;

This ends up creating a new string instead of actually erasing the characters from the old string, but it is a little easier to wrap your head around than using some of the more complex built in functions.