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A little problem

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WesFox13 WesFox13 is offline Offline
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A little problem

 
0
  #1
Nov 5th, 2008
Hey all I've been writing a program that cheks an ISBN number as valid or invalid as an assignment for a class but I need a little bit of help. I get these errors when I try to compile it:

error C2275: 'std::string' : illegal use of this type as an expression
error C2275: 'std::istream' : illegal use of this type as an expression
error C2062: type 'char' unexpected

and the complier says this is the line repsonsible for the error.
getline(istream& fin, string& num_of_isbn, char '\n');
these are the only errors I have in my program

Any help on this problem?

Here's the full code
C++ Syntax (Toggle Plain Text) 
  1.  ///
  2. ///
  3. /// Wesley Montgomery
  4. /// 11/05/2008
  5. /// CS 210
  6. /// Prof. Gelotte
  7. /// Section A (9:30-10:20)
  8.  
  9. // THIS IS PROGRAM 4 (ISBN-Check), a program that verifies ISBN numbers.
  10.  
  11. #include <iostream>
  12. #include <fstream>                                                           // REQUIRED FOR FILE STREAMS
  13. #include <cstdlib>                                                         // FOR DEFINITION OF EXIT_FAILURE
  14. #include <cctype>
  15. #include <string>
  16. using namespace std;
  17.  
  18. // ASSOCIATE STREAMS WITH EXTERNAL FILE NAMES
  19. #define inFile "isbntest.txt"                                          // LINKED ISBN FILE (LIST) SOURCE
  20.  
  21. // FUNCTIONS USED
  22. void menuPrompt ();                                             // MAIN MENU USER INSTRUCTION
  23. void userVal ();                                                 // MANUAL INPUT VALIDATION
  24. int readFile ();                                                   // LINKED FILE VALIDATION
  25. bool isbnCheckForUser (string isbn);                              // ISBN VALIDATION FUNCTION FOR USER INPUT
  26. bool isbnCheckForFile (string isbn);                        // ISBN VALIDATION FUNCTION FOR FILE INPUT
  27.  
  28. int main ()
  29. {
  30.     char choice;                                           // INPUT-MAIN MENU CHOICE
  31.     string isbn;
  32.  
  33.         do
  34.         {
  35.             menuPrompt ();
  36.             cin >> choice;
  37.             switch (choice)
  38.             {
  39.             case '1':
  40.                     userVal ();
  41.                     break;
  42.             case '2':
  43.                     readFile ();
  44.                     break;
  45.             case '3':
  46.                     cout << "Thank you for using ISBN-Check. Have a nice day!" << endl;
  47.                     break;
  48.             default:
  49.                     cerr << "Oops! Incorrect selection. Please try again." << endl;
  50.             }            
  51.         }
  52.         while (choice != '3');
  53.  
  54.     system ("pause");
  55.  
  56.     return 0;
  57. }
  58.  
  59. void menuPrompt ()
  60. {
  61.     cout << "Welcome to ISBN-Check." << endl;
  62.     cout << "This program will verify the format of your ISBN(s)." << endl;
  63.     cout << "To manually input the ISBN(s), enter 1." << endl;
  64.     cout << "To verify the ISBN(s) from the linked .txt file, etner 2." << endl;
  65.     cout << "When you're done, enter 3 to exit the program." << endl;
  66. }
  67.  
  68. void userVal ()
  69. {
  70.     char subchoice;                                                                            // INPUT- SUB MENU CHOICE
  71.     string isbn;                                                                            // INPUT- ISBN STRING
  72.     do
  73.     {
  74.     cout << "Enter an ISBN:";
  75.     cin >> isbn;
  76.     isbnCheckForUser (isbn);
  77.     if (isbnCheckForUser (isbn) == true)
  78.         cout << "This is a valid ISBN." << endl;
  79.     else
  80.         cout << "This is NOT a valid ISBN." << endl;
  81.     cout << endl;
  82.     cout << "To go back to the main menu, enter 1." << endl;
  83.     cout << "To continue manually inputting ISBN(s), enter any digit besides 1." << endl;
  84.     cin >> subchoice;
  85.     }
  86.     while (subchoice != '1');
  87.  
  88. }
  89.  
  90. int readFile ()
  91. {
  92.     ifstream fin;
  93.     string isbn;
  94.     fin.open (inFile);
  95.     if (fin.fail ())
  96.     {
  97.         cerr << " ERROR: Cannot open " << inFile << " for input. " << endl;
  98.         return EXIT_FAILURE;                                                                // FAILURE RETURN
  99.     }
  100.     fin >> isbn;
  101.     isbnCheckForFile (isbn);
  102.     if (isbnCheckForFile (isbn) == true)
  103.         cout << "This is a valid ISBN." << endl;
  104.     else
  105.         cout << "This is NOT a valid ISBN." << endl;
  106.  
  107. }
  108.  
  109. bool isbnCheckForUser (string isbn)
  110. {
  111.     int isbn0;
  112.     int isbn1;
  113.     int isbn2;
  114.     int isbn3;
  115.     int isbn4;
  116.     int isbn5;
  117.     int isbn6;
  118.     int isbn7;
  119.     int isbn8;
  120.     int isbn9;
  121.     int sum;
  122.     int modulo;
  123.  
  124.     if (isbn.at(0) == '-' || isbn.at(isbn.length()-1) == '-')
  125.         cout << "This is NOT a valid ISBN." << endl;
  126.  
  127.         isbn.find('-');                                
  128.         isbn.erase('-');
  129.         isbn.at(0) = isbn0;
  130.         isbn.at(1) = isbn1;
  131.         isbn.at(2) = isbn2;
  132.         isbn.at(3) = isbn3;
  133.         isbn.at(4) = isbn4;
  134.         isbn.at(5) = isbn5;
  135.         isbn.at(6) = isbn6;
  136.         isbn.at(7) = isbn7;
  137.         isbn.at(8) = isbn8;
  138.         isbn.at(9) = isbn9;
  139.  
  140.     if (isbn.at(isbn.length()-1) == 'x' || isbn.at(isbn.length()-1) == 'X')
  141.         isbn9 = 10;
  142.  
  143.     sum= isbn0 * 1 + isbn1 * 2 + isbn2 * 3 + isbn3 * 4 + isbn4 * 5 + isbn5 * 6 + isbn6 * 7 + isbn7 * 8 + isbn8 * 9;
  144.     modulo = sum / 11;
  145.  
  146.     if (modulo = 10 && isbn.at(isbn.length()-1) == 'x' || isbn.at(isbn.length()-1) == 'X')
  147.         cout << "This is a valid ISBN." << endl;
  148.  
  149.     else if (modulo = 10 && isbn.at(isbn.length()-1) != 'x' || isbn.at(isbn.length()-1) != 'X')
  150.         cout << "This is NOT a valid ISBN." << endl;
  151.  
  152.     else if (modulo != isbn9)
  153.         cout << "This is Not a valid ISBN." << endl;
  154.  
  155.     else
  156.         cout << "This is a valid ISBN." << endl;
  157. }
  158.  
  159. bool isbnCheckForFile (string isbn)
  160. {
  161.     ifstream fin;
  162.     int num_of_isbn;
  163.     int count;
  164.     int isbn0;
  165.     int isbn1;
  166.     int isbn2;
  167.     int isbn3;
  168.     int isbn4;
  169.     int isbn5;
  170.     int isbn6;
  171.     int isbn7;
  172.     int isbn8;
  173.     int isbn9;
  174.     int sum;
  175.     int modulo;
  176.  
  177.     getline(istream& fin, string& num_of_isbn, char '\n');
  178.     fin.ignore( 80, '\n');
  179.     while (!fin.eof())
  180.         {
  181.             for (count=0; count < num_of_isbn; count++)
  182.                 {
  183.                     getline (fin, isbn);
  184.                     if (isbn.at(0) == '-' || isbn.at(isbn.length()-1) == '-')
  185.                     cout << "This is NOT a valid ISBN." << endl;
  186.                     isbn.find('-');                                //HOW DO I COUNT THE NUMBER OF DASHES?
  187.                     isbn.erase('-');
  188.                     isbn.at(0) = isbn0;
  189.                     isbn.at(1) = isbn1;
  190.                     isbn.at(2) = isbn2;
  191.                     isbn.at(3) = isbn3;
  192.                     isbn.at(4) = isbn4;
  193.                     isbn.at(5) = isbn5;
  194.                     isbn.at(6) = isbn6;
  195.                     isbn.at(7) = isbn7;
  196.                     isbn.at(8) = isbn8;
  197.                     isbn.at(9) = isbn9;
  198.                     if (isbn.at(isbn.length()-1) == 'x' || isbn.at(isbn.length()-1) == 'X')
  199.                     isbn9 = 10;
  200.                     sum= isbn0 * 1 + isbn1 * 2 + isbn2 * 3 + isbn3 * 4 + isbn4 * 5 + isbn5 * 6 + isbn6 * 7 + isbn7 * 8 + isbn8 * 9;
  201.                     modulo = sum / 11;
  202.                     if (modulo = 10 && isbn.at(isbn.length()-1) == 'x' || isbn.at(isbn.length()-1) == 'X')
  203.                     cout << "This is a valid ISBN." << endl;
  204.                     else if (modulo = 10 && isbn.at(isbn.length()-1) != 'x' || isbn.at(isbn.length()-1) != 'X')
  205.                     cout << "This is NOT a valid ISBN." << endl;
  206.                     else if (modulo != isbn9)
  207.                     cout << "This is Not a valid ISBN." << endl;
  208.                     else
  209.                     cout << "This is a valid ISBN." << endl;
  210.                 }
  211.         }
  212. }
Last edited by WesFox13; Nov 5th, 2008 at 2:25 pm. Reason: inserted rest of code
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Re: A little problem

 
0
  #2
Nov 5th, 2008
C++ Syntax (Toggle Plain Text) 
  1. getline(istream& fin, string& num_of_isbn, char '\n');

This isn't a function call. It's a function prototype already defined in C++, so you don't need to define it. Leave the variable types out. The compiler will figure out what the types are and what function to call:

C++ Syntax (Toggle Plain Text) 
  1. getline (fin, num_of_isbn, '\n');

This would be a proper function call. It won't work in your program because you have num_of_isbn defined as an integer in line 162 above. You have to read it into a string or char* and then convert it to an integer if you want to use this getline function. I don't know what your input file looks like, but is there a reason you aren't doing this?

C++ Syntax (Toggle Plain Text) 
  1. fin >> num_of_isbn;
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