c++ - Boolean operator problems -

simple code here, i'm trying write code can pick on specific keywords, i'm not having lot of luck. here's code:

#include <iostream> int main(){     std::string input;     bool isunique = true;      std::cout<<"please type word: ";     std::cin>>input;      if(input == "the" || "me" || "it"){         isunique = false;     }     if(isunique){         std::cout<<"unique!!"<<std::endl;     }     else         std::cout<<"common"<<std::endl; } 

if type in of 3 words (in if statement), you'll proper output program ("common"). however, if type else, you'll same exact output. if limit program search 1 word (ie: "the") , test it, works should, there 2 or more keywords, program lists "common". i've tried replacing or statements commas didn't anything. code i'm trying implement going have 50+ keywords i'm trying find efficient way search these words.

you have change:

if(input == "the" || "me" || "it") 

to:

if(input == "the" || input == "me" || input == "it") 

the way operator || works in a || b each clause a , b evaluated (if ever) on it's own. b not care context of a.

so in case following 3 expressions might evaluated (the last 1 never):

1. input == "the"
2. "me"
3. "it"

the first 1 may or may not result in true, second 1 will.

---

you can rewrite code to:

int main() {     std::cout << "please type word: ";     std::string input;     std::cin >> input;      auto common_hints = {"the", "me", "it"};     if (std::find(begin(common_hints), end(common_hints), input) != end(common_hints)) {         std::cout << "common\n";     } else {         std::cout << "unique!!\n";     } } 

live demo

or (using boost):

int main() {     std::cout << "please type word: ";     std::string input;     std::cin >> input;      auto common_hints = {"the", "me", "it"};     if (boost::algorithm::any_of_equal(common_hints, input)) {         std::cout << "common\n";     } else {         std::cout << "unique!!\n";     } } 

live demo