Searching the last character of a string for punctuation - c++

Question

I'm currently working on making a little word processor and I've come across an issue. I'm trying to make the program so that when you press enter, the program will put a full stop on your input and then a space (I'll sort out paragraphs later). The issue is that I can't get the program to search the last character for punctuation and then branch on the result. The compiler gives me the following error: ISO C++ forbids comparison between pointer and integer. The code I currently have is:
#include <fstream>
#include <string>
#include <iostream>
#include <cstring>
#include <limits>
using namespace std ;
int main()
{
int i = 0;
string text ;
string text2 ;
string title ;
string usertitle ;
string filelocation = "C:/Users/" ;
string user ;
string punctuation = ". : ! ? "
cout << "Input a title for your file: " ;
getline(cin , title) ;
title.insert(title.length() , ".txt" ) ;
cout << "Your title is: " << title << endl ;
cout << endl << "Input the username associated with your computer: " ;
getline(cin , user) ;
filelocation.append( user ) ;
filelocation.append("/Documents/") ;
filelocation.append(title) ;
cout << "Your chosen file name and location is: " << filelocation << endl ;
for ( i = 1 ; i > 0 ; i++ )
{
if (text == "")
{
cout << "There are a few instructions that you need to follow in order to use this system effectively: " << endl ;
cout << "The first being that if you want to use it, you actually have to use a directory that exists. " << endl ;
cout << "The second being that when you want to exit the program you press enter with nothing typed" << endl ;
cout << "The third being NOT TO USE FULL STOPS, THE PROGRAM WILL PUT THEM IN FOR YOU" << endl ;
cout << "Please begin writing: " << endl ;
getline(cin,text) ;
}
if (text!="")
{
text2.append(text) ; //<===HERE IS WHERE I AM HAVING TROUBLE
if ((text.at(text.size() -1 ) != "!" ) && (text.at(text.size() -1 ) != "?") && (text.at(text.size() -1 ) != ":" ))
{
text2.append(". ") ;
getline(cin, text) ;
}
else
{
getline(cin, text) ;
}
if (text == "")
{
cout << "End of session" << endl ; break ;
}
}
}
ofstream writer( filelocation.c_str() ) ;
if(! writer)
{
cout << "Error opening file for output: " << strerror(errno) << endl ;
return -1 ;
}
else
{
writer << text2 << endl ;
writer.close() ;
}
return 0 ;
}
Thanks for your help in advance!

Answer 1

"!" is a string, you want to compare against a character: '!'.

Answer 2

You can't compare "!" and '!'.
I suggest using rbegin() to address the last character:
text2.append(text.begin(), text.end());
switch(*text.rbegin())
{
case '!':
case '?':
case ':': text2.append(". "); break;
}
getline(cin, text);
if(text.empty())
{
cout << "End of session" << endl;
break;
}

Answer 3

if ((text.at(text.size() -1 ) != "!" ) && (text.at(text.size() -1 ) != "?") && (text.at(text.size() -1 ) != ":" ))
That is both inefficient and is not doing what you think. text.at(text.size() -1 ) returns the last character. To get what you want:
char lastChar = text[text.size() - 1]; // or char lastChar = *text.rbegin();
if (!(lastChar == '.' || lastChar == '?' || lastChar == '!')) // note the single quotes
{
text2.append(". ");
}
getline(cin, text);