No match for 'operator==' in a simple string code

Question

Writing a simple code and ran into a problem I\'m not sure how to deal with. I tried looking into it with a search but nothing I found was much help and everyone\'s answers wer

Answer 1

 #include 
 #include 

 using namespace std;

 int main()
 {
     string invCode = "";
     string lastTwoChars = "";

     cout << "Use this program to determine color of furniture.";
     cout << "Enter five-character inventory code: ";
     cin >> invCode;

     if (invCode.length() == 5)
     {
         lastTwoChars = invCode.substr(3,2);
          if (lastTwoChars == "fourty five") // you declared lastTwoChars as string therefore you have to compare letters not integers which are numbers.
          { 
               cout << "Red";
          }
     if (lastTwoChars == "twenty five") //same
     { 
          cout << "Black";
          }
     if (lastTwoChars == "thirty") // same
     { 
          cout << "Green";
          }
}
else
     cout << "Invalid inventory code." << endl;

cin.get(); // better than system("pause");
return 0;
}