C++ beginner help!

Marcus1992 (3)

Hello! I've recently started messing around with c++ (been doing it for about 4 weeks) and I'm trying to make a simple calculator with 4 basic "countings". But I've come across a problem and I need some help from someone more knowledgeable.

The problem is that when I run my program and choose for example option 1 I should get to the addition section but instead the program freezes for about 15 seconds and then shut down on me.

Another thing I would like to add to my program is a system("cls") so that the screen is cleared when you come back to the menu but I've had some problems with this and would be happy if I could get some help with that aswell.

Btw, the notes and some other stuff are in swedish but you should be able to read the code anyway :)

So here's the code!

#include <iostream>
#include <stdlib.h>
 
using namespace std;
void meny();
void addition();
void subtraktion();
void multiplikation();
void division();
 
 
 
double a, b, c;
int val;
 
main()
 
{
      meny(); //kallar på meny
      }
 
void meny()
{
     int val;
 
     cout <<" 1: Addition n 2: Subtraktion n 3: Multiplikation n 4: Division n 5: Avslutann";
 
     cin >>val;
 
     switch(val)
     {
                case 1:addition();break;
                case 2:subtraktion();break;
                case 3:multiplikation();break;
                case 4:division();break;
                default: cout <<"Tack för att du testade min miniräknare!";
                }
     }
 
     void addition() //Skapar funktionen addition
{
     double a,b,c;
     int i;
     system("cls");
     c=a+b;
     cout<<"Ange två tal som du vill addera.";
     cin>>a>>b;
     cout<<"Summan av dina tal är "<<c<<".";
     cout<<"nnTryck 1 för att komma tillbaka till menyn.";
     cin>>i;
     if(i==1)
     meny(); //Går till menyn
     system("pause");
 
     }
 
void subtraktion() //Skapar funktionen subtraktion
{
     double a,b,c;
     int i;
     system("cls");
     c=a-b;
     cout<<"Ange två tal som du vill subtrahera.";
     cin>>a>>b;
     cout<<"Differensen av dina tal är "<<c<<".";
     cout<<"nnTryck 1 för att komma tillbaka till menyn.";
     cin>>i;
     if(i==1)
     meny(); //Går till menyn
     system("pause");
     }
 
void multiplikation() //Skapar funktionen multiplikation
{
     double a,b,c;
     int i;
     system("cls");
     c=a*b;
     cout<<"Ange två tal som du vill multiplicera.";
     cin>>a>>b;
     cout<<"Produkten av dina tal är "<<c<<".";
     cout<<"nnTryck 1 för att komma tillbaka till menyn.";
     cin>>i;
     if(i==1)
     meny(); //Går till menyn
     system("pause");
     }
 
void division() //Skapar funktionen division
{
     double a,b,c;
     int i;
     system("cls");
     c=a/b;
     cout<<"Ange två tal som du vill subtrahera.";
     cin>>a>>b;
     cout<<"Kvoten av dina tal är "<<c<<".";
     cout<<"nnTryck 1 för att komma tillbaka till menyn.";
     cin>>i;
     if(i==1)
     meny(); //Går till menyn
     system("pause");
     }

Thanks in advance!

Moschops (7244)

You are calling meny() over and over and over again, from within functions that are within meny(). In C++, when you call a function, a whole new set of memory is taken up, and whole new variables created. This is known as a "stack frame". Calling a function over and over again from inside itself creates an endless run of these stack frames. http://en.wikipedia.org/wiki/Call_stack

This is very very bad. You should not repeat meny by calling it again. You should repeat it using a loop.

system("cls") is bad. Here is something better:
http://www.cplusplus.com/articles/4z18T05o/

That all said, when I run your code, I do not see the problem you describe. Here is some sample output:

 1: Addition n 2: Subtraktion n 3: Multiplikation n 4: Division n 5: Avslutann1
Ange tvÕ tal som du vill addera.3
4
Summan av dina tal õr 4.83694e-307.nnTryck 1 f÷r att komma tillbaka till menyn.1

 1: Addition n 2: Subtraktion n 3: Multiplikation n 4: Division n 5: Avslutann1
Ange tvÕ tal som du vill addera.4
2
Summan av dina tal õr 4.83694e-307.nnTryck 1 f÷r att komma tillbaka till menyn.

Last edited on

Gaminic (1621)

Out of curiosity: would replacing 32-35 with "return addition()" etc technically fix it, or would that still start the new call before ending the old one?

Marcus1992 (3)

Thanks for a quick reply!

As I said in the first post I've only been doing this for a very short time and I'm not very familiar with creating loops so some help on how I might add it in my code would be nice!

Also, as I understand it I should include conio.h and use clrscr(); instead of system("cls")?

That all said, when I run your code, I do not see the problem you describe. Here is some sample output:

I tried running it again and still have the same problem :/
Thanks again.

Last edited on

Gaminic (1621)

Your loop could look something like this:

int i;
do {
   meny();

   cout << "Continue? 1 for yes, 0 for no!\n";
   cin >> i;
} while (i == 1);

That way, the menu will be called up as long as the user keeps inputting '1' when the question appears.

Need4Sleep (570)

Your Int main should use a while loop and a bool like so

Do{
Meny()
Cin >> y/n
\\set game to true is yes, and no if n is entered 
}while(game)

This way menu will always repeat as long as you'd like

Sorry if the code is written weird, wrote this on my phone!

Last edited on

Marcus1992 (3)

Thanks alot, seems that after I changed it to a loop the freezing issue went away as well :)

Topic archived. No new replies allowed.

C++

Forum

C++ beginner help!