How to use nested getline() function to get ride of special characters and punctuation in a string?

Question

I am using getline() function to get ride of special characters and punctuation in a sentence, so that when i display the words contained in the sentence, it does not have any other character beside a-z (or A-Z). The problem is that it gets long, and I don't think it is really efficient. I would like to know if I can do it in a efficient way. I am using Dev-C++, the code below is in C++. Thanks for your help.

#include <string>
#include <iostream>
#include <ctype.h>
#include <sstream>

using namespace std;



int main()
{
 int i=0;
 char y; 
 string prose, word, word1, word2;
 cout << "Enter a sentence: ";
 getline(cin, prose);

 string mot;
 stringstream ss(prose);


 y=prose[i++];
 if (y=' ')   // if character space is encoutered...


  cout<<endl << "list of words in the prose " << endl;
  cout << "---------------------------"<<endl;
  while(getline(ss, word, y))  //remove the space...
   {

      stringstream ss1(word);      

     while(getline(ss1, word1, ','))  //remove the comma...
       {

          stringstream ss2(word1);  //remove the period
          while(getline(ss2, word2, '.'))
           cout<< word2 <<endl; //and display just the word without space, comma or period.
       }
   }      


     cout<<'\n';
    system ("Pause");
    return 0;
}

#############################output

Enter a sentence: What? When i say: "Nicole, bring me my slippers, and give me m y night-cap," is that prose?

list of words in the prose

What? When i say: "Nicole bring me my slippers and give me my night-cap " is that prose?

Press any key to continue . . .

Answer 1

Use std::remove_if():

std::string s(":;[{abcd 8239234");

s.erase(std::remove_if(s.begin(),
                       s.end(),
                       [](const char c) { return !isalpha(c); }),
        s.end());

If you do not have a C++11 compiler, define a predicate instead of using a lambda (online demo http://ideone.com/NvhKq).