HELP WITH FUNCTIONS and POINTERS!!!
I have a shell of a program and I am suppose to input the rest of the functions, though I am trying to figure out if I am doing this correctly. I have inputed one of the functions but it doesn't seem to work. Can anyone let me know if it seems like i Am doing it correctly....
Code:
#include <iostream>
#include <iomanip>
using namespace std;
/* Struct to define a book */
struct BOOK_STRUCT { char title[40],
char author[40],
char isdn[10];
};
/*Function Name: check_out_book
Parameters: A book
Purpose: Function checks out a book. Nothing is returned.
*/
void check_out_book (BOOK_STRUCT* book)
{
}
/*Function Name: get_book_by_title
Parameters: A library of books, a title, and the size of the library
Purpose: Function returns a pointer to a book based on the title supplied
by the user. If the book is not found, a null pointer is returned.
*/
BOOK_STRUCT* get_book_by_title (BOOK_STRUCT library[], char* title, int lib_size)
{
}
/*Function Name: print_avail_books
Parameters: A library of books and the size of the library
Purpose: Function goes through the library and prints only those books
which are not checked out.
*/
void print_avail_books (BOOK_STRUCT library[], int lib_size)
{
int row;
cout<<endl<<endl;
cout<<setw(20)<< "title"
<<setw(20)<< "author"
<<endl;
for(row = 0; row < lib_size; row; ++row)
{
cout<<setw(20) << library[row].title
<<setw(20) << author[row].author;
}
}
int main()
{
char in_title[81]; // buffer to contain input from user
BOOK_STRUCT* book; // a book pointer
int choice=0; // used by the menu
int NUM_BOOKS = 2; // number of books in the library
// library data structure
BOOK_STRUCT library[] = {{"Gods and Generals", "Jeff Shaara", "123", 0},{"Killer Angels",
"Michael Shaara", "143", 0}};
cout << setprecision(2)
<< setiosflags(ios::fixed)
<< setiosflags(ios::showpoint);
// Output message to user
cout<<"Welcome to Fraser Library"<<endl;
// Loop until the user selects exit.
do{
cout<<"Please select from the following options."<<endl;
cout<<"1. Search for a book."<<endl;
cout<<"2. Print available books."<<endl;
cout<<"3. Checkout a book."<<endl;
cout<<"4. Exit"<<endl;
cout<<" > ";
cin>>choice; //read input
if(cin.good() && choice > 0 && choice < 5){ // Make sure choice is correct
if(choice == 1 || choice == 3){ // selections require title of the book
cin.ignore(); // need to ignore the character return from the previous cin
cout<<"Please enter the title of the book."<<endl<<" > ";
cin.getline(in_title,81); //read input from user
book = get_book_by_title(library, in_title, NUM_BOOKS); // get book
if (book == NULL) // The book is not in the library
cout<<endl<<in_title<<" not found. Please try another title"<<endl<<endl;
else if (book->checked_out == true) // The book is available but checked out
cout<<endl<<"Sorry, "<<book->title<<" is checked out. Please try another title"<<endl<<endl;
else if (choice == 1) // The book is available and it will be checked out
cout<<endl<<book->title<<" by "<<book->author<<" is available."<<endl<<endl;
else{ // The book is available
cout<<endl<<book->title<<" is available. I'll check it out for you now."<<endl<<endl;
check_out_book(book);
}
}
else if(choice == 2){ // user wants to print the list of books
print_avail_books(library, NUM_BOOKS);
}
else{ //user selected exit
cout<<"Thanks for coming!"<<endl;
return 0;
}
}
else { //user provided something we can't understand
cout<<endl<<"Sorry, I don't understand what you selected. Please try again"<<endl<<endl;
choice = 1; // This just makes sure the user gets a chance make another selection
}
}
while(choice < 4);
return 0;
}
