CODEWITHSUNDEEP
c++language-lawyer
Kdizzile
Kdizzile

Reputation: 29

Cant call int main to repeat program c++

For some reason, my program wont let me call main. Im trying to make the program repeat so i can keep adding stuff into main, but it will pretend like main isnt there and skip it.

Heres my code, ive tracked it line by line and even when i enter in the correct info it just refuses to read in the int main(); Any thoughts?

edit: im a moron. Thanks for the help!

#include <iostream>

using namespace std;

,,,

int main()
{
    // New OrderedList
    OrderedList OrderedList;//no constructor called - is head initialized to NULL?
    char repeat;

    int choice = 0, data;

    cout << "Choose from the following menu options,\n"
         << "1: Add an item\n"
         << "2: Search for an item\n"
         << "3: Delete an item\n"
         << "4: Display the list\n"
         << "5: Destroy the list\n";
    cin >> choice;

        if (choice <= 3)
    {
        cout << "\nPlease enter the item.";
        cin >> data; 
    }
    switch(choice)
    {
    case 1:
        OrderedList.Insert(data);
        break;
    case 2: 
        OrderedList.Search(data);
        break;
    case 3: 
        OrderedList.Delete(data);
        break;
    case 4:
        OrderedList.Print();
        break;
    case 5:
        //delete OrderedList; "no constructor called - is head initialized to NULL?"
        break;
    }

    cout << "Repeat Y/N?\n";
    cin >> repeat;

    if (repeat == 'y' || repeat == 'Y')
    int main();
    return 0;
}

Upvotes: 0

Views: 963

Answers (4)

2785528
2785528

Reputation: 5576

Do not call main. Instead, use the following 1 liner

int main(int argc, char* argv[]) { 
   return (myMain(argc, char* argv[]);) 
}

to use your own main ... which can be called recursively.

int myMain(int argc, char* argv[]) 
{
   // what ever you want, including recursion, 
   // but do not call what you are using for "int main(int, char**)"
}

However, now you should be able to see that "main" has special meaning to all of your peers, so there is only confusion in using any variation on "main".

Example: in my file "dumy142.cc", I prefer to use a (somewhat) more meaningfull name, such as "int t142(int argc, char* argv[])":

int main(int argc, char* argv[]) {
   return(t142(arc, argv);
}

Upvotes: 1

rzaaeeff
rzaaeeff

Reputation: 880

You should never call main function inside your application, instead you can try using while loop.

int main(){    
   char repeat = 'Y';

   while( repeat == 'y' || repeat == 'Y' )    
   {
      //do some stuff

      cout << "Repeat? Y/N" << endl;
      cin >> repeat;    
   }

   return 0; 
}

Good luck!

Upvotes: 4

vsoftco
vsoftco

Reputation: 56577

You just shouldn't call main() recursively, in fact, you shouldn't call it at all. In fact, the C++ standard forbids calling using main in a "potentially evaluated expression", see §3.6.1.3 from the standard (as pointed out by @Captain Obvlious). main() is the C++ startup function of your program, invoked by the runtime library after all other (possible) initializations have been performed.

If you want to repeat what it's in main(), just use a while (or for) loop.

PS: the following seem to work:

Use a static variable as a stop condition, and call main() recursively, however I have to say I have never seen this practice, and I wouldn't recommend it at all. Just tested that this works:

#include <iostream>
using namespace std;

// calling main() 10 times, recursively
int main() {
    static int i = 10; 
    cout << "Hello, World!" << endl; 

    i--;
    if(i>0)
        main();
}

However, if you compile with -pedantic or -pedantic-errors, you'll get a warning/error respectively, stating that you shouldn't/cannot call main();

Upvotes: 3

Wintermute
Wintermute

Reputation: 44063

If you change the line

int main();

(which is a function declaration) to

main();

which would be a function call, it is likely going to work. However, it would be better to wrap the contents of main in a loop.

EDIT: I just checked the standards, and interestingly, recursive calls to main are only illegal in C++. I find that surprising.

EDIT 2: Oh, the question is tagged C++. In that case, you are forbidden from calling main recursively! Demons will come out of your nose and whatnot.

Upvotes: 2

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