c++ - cin in a while-loop -

#include <iostream>  using namespace std;  int main() {     string previous;     string current;      while (cin >> current)     {         if(current == previous)         {             cout << "repeated word";         }          previous=current;     }      return 0; } 

my questions are:

1. when states while(cin>>current), why entire entered string of text not assigned current? don't understand how compares words individually.

2. how word previous. how know 2 of same words adjacent?

edit: think understood why. tell me if wrong think because compiler stops cin assignment @ space , first word assigned current, compares previous word, since first word, not have previous word assigned first word previous , compares next word in sentence until there no more words left. i'm how works going leave in case ever wondering similar.

1. the default behavior stop on whitespace when reading strings doing. can change read whitespace saying std::cin >> std::noskipws.
2. the previous word assigned @ end of loop. given answer part 1, should clear why previous works.