Is return Main() a good idea?

[Blackhart98]

Hello, I'm trying to loop back through the menu instead of it exiting. I did came to the conclusion of return back to main(). Never tried it before but it worked. Is there another way to do this?

  #include <iostream>
#include <iterator>
using namespace std;
class Listthenodes
{
private:
    typedef struct nodes
    {
        int Numbers;
        nodes* next;

    }*Nodeptr;

Nodeptr head;
Nodeptr curr;
Nodeptr temp;

public:
    Listthenodes();
void Addnode(int addData);
void DeleteNode(int delnode);
void DisplayData ();

};
Listthenodes::Listthenodes()
{
    head = NULL;
    temp = NULL;
    curr = NULL;
}
void Listthenodes::Addnode(int addData)
{
    Nodeptr n = new nodes;
    n->next = NULL;
    n->Numbers = addData;

    if (head != NULL)
    {
        curr = head;
        while (curr->next != NULL){
            curr = curr->next;
        }
        curr->next = n;
    }

    else
        {

    head = n;
        }
}
void Listthenodes::DeleteNode(int delnode)
{
    Nodeptr d = NULL;
    temp = head;
    curr = head;
    while (curr != NULL && curr -> Numbers != delnode){
        temp = curr;
        curr = curr->next;
    }
    if(curr == NULL){

        cout << delnode << "Was not in the list" << endl;
    }
    else
    {
        d = curr;
        curr = curr->next;
        temp -> next = curr;
        delete d;
        cout << "The value" << delnode << " Was deleted" << endl;
    }
}
void Listthenodes::DisplayData()
{
    curr = head;
    while (curr != NULL){
        cout << curr->Numbers << endl;
        curr = curr->next;

    }

}



int main()
{
Listthenodes Justin;
int Bo;


int x;
    cout << "1 . Add to node" << endl;
    cout << "2 . Delete a node" << endl;
     cout << "3 . Display nodes" << endl;
      cout << "4 . Exit program" << endl;
  cin >> x;
    switch (x)
    {


    case 1:{
         cout << "Add an node" << endl;
        cin >> Bo;

        Justin.Addnode(Bo);

return main();

break;
    }


    case 2:
        {
break;
        }


    case 3:
        {
break;
        }


    case 4:
        {

break;
        }


    }
}

[Ganado]

No, it is never okay to call main(). main is a special function that is only the entry point to the program. Use a while loop inside main instead.


rough example:

int main()
{
    Listthenodes Justin;
    int Bo;
    while (true) {
        int x;
        cout << "1 . Add to node" << endl;
        cout << "2 . Delete a node" << endl;
        cout << "3 . Display nodes" << endl;
        cout << "4 . Exit program" << endl;
        cin >> x;
        switch (x)
        {
          case 1:
            cout << "Add an node" << endl;
            cin >> Bo;
            Justin.Addnode(Bo);
            continue;  // goes to top of while loop again

        }
    }
}

[andywestken]

Is return Main() a good idea?

No - it's a bad idea.

The C++ Standard actually says that you may not call main() from your own code. But as C allows it is seems that compilers let you get away with it.

Is there another way to do this?

Yes.

Here you should use a while loop.

(But if you do come across an actual need for a recursive main, move the contents out of main into your own function and then call it recursively.)

Andy

[Blackhart98]

@andywestken @Ganado

Thanks.