windows - C++ Issue with cin and CTRL + Z -

i'm reading c++ primer 5th , have little problem exercise:

read sequence of words cin , store values vector. after you’ve read words, process vector , change each word uppercase. print transformed elements, 8 words line.

my code this:

#include <iostream> #include <vector> #include <string> #include <cctype>  using std::vector; using std::string; using std::cin; using std::cout; using std::endl;  int main(){      vector<string> words;     string wordbuffer;     vector<string> output(1);      while (cin >> wordbuffer){         words.push_back(wordbuffer);     }      (string &word : words){         (char &letter : word){             letter = toupper(letter);         }     }      unsigned currentline = 0;     (decltype(words.size())index = 0; index < words.size(); ++index){          output[currentline] += words[index] + " ";          if ((index+1) % 8 == 0){             ++currentline;             output.push_back("");         }      }      (string s : output){         s[s.size() - 1] = 0; //removing whitespace         cout << s << endl;     }      system("pause");     return 0; } 

now, works well, have issue input of words console.
if write

i writing random words ^z

and press enter nothing happens. have rewrite ^z after have pressed enter, here:

i writing random words
^z

can expain me why? thanks!

ps: i'm saying because in previous programs writing ^z in same line worked fine. in code:

#include <iostream>;   int main(){     int currval = 0,val = 0;          int count = 1;         while (std::cin >> val){             if (currval == val){                 ++count;             }             else {                 std::cout << "the number " << currval << " appears " << count << " times" << std::endl;                 currval = val;                 count = 1;             }         }         std::cout << "the number " << currval << " appears " << count << " times" << std::endl;      system("pause");      return 0; } 

i can't figure out why :(

the ^z has first in order windows treat ctrl+z, otherwise treated meaningless characters.

if work wrote i'd suggest:

string wordbuffer("") while (strcmp(wordbuffer[strlen(wordbuffer)-3], "^z") != 0){     words.push_back(wordbuffer);     cin >> wordbuffer } 

edit: in second example works because when read integers c++ knows divide given string of numbers in space (or enter if numbers entered separately in every line) read every number separately if you'll enter:

123 2323 4545 43 ^z 

it read 123, 2323, ... , ^z , though got in separate line when read string, cant because string contain every symbol , separate input in enter pressed , why second 1 works