how to sort a string

string sort (string s) {
    int n = s.length();
    for (int i = 0; i < n-1; i++) {
        for (int j = i+1; j < n; j++) {
            if (s[i] > s[j]) {
                char temp = s[i];
                s[i] = s[j];
                s[j] = temp;
            }
        }
    }
    return s;
}