Why does it return zero when counting?

PenguinMan · 10-23-2002, 11:10 PM

The program should see if you entered an odd /even or a zero and display how many of each you inputed. On the code here i dont have a loop yet.

Here is the code and the output.
#include <iostream.h>

int classifynumber (int number, int zerocount, int oddcount, int evencount);

int main () {

int zerocount;
zerocount=0;

int oddcount;
oddcount=0;

int evencount;
evencount=0;

cout<<"Enter 1 number"<<endl;
int number;
cin>>number;

int classifynumber (int number, int zeros, int odds, int evens);

cout <<"the number you entered "<< number <<" there are evecount: "<< evencount <<" oddcount " <<oddcount <<" zerocount: "<< zerocount<<endl;
return 0;

}

int classifynumber(int number, int zerocount, int oddcount, int evencount)
{

switch(number%2)
{
case 0:
evencount++;
if (number==0)
zerocount++;
break;
case 1:
case -1: oddcount++;
}

return number;
}

===================================================
Enter 1 number
3
the number you entered 3 there are evecount: 0 oddcount 0 zerocount: 0

----------------------------------------------
Program exited successfully with errcode (0)
Press the Enter key to close this terminal ...

what am i doing wrong?

ferrous · 10-24-2002, 03:49 AM

Answer: C++ defaults to pass-by-value parameters. You want to use pass-by-reference for your classifynumber function.

Simple answer: You want to put ampersands in front of zerocount, oddcount, and evencount in the declaration (and prototype) of classifynumber.

GtkUser · 10-24-2002, 09:56 AM

Based on what you provided, here is a running program.

Code:

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

void classifynumber (const int number, int &zerocount, int &oddcount, int &evencount);


int main () {
    
  int zerocount = 0;
  int oddcount = 0;
  int evencount = 0;
  int number;

  cout << "Enter a number: ";
  cin >> number;
	
  classifynumber (number, zerocount, oddcount, evencount);

  cout <<"the number you entered "<< number <<" there are evencount: "<< evencount <<" oddcount " <<oddcount <<" zerocount: "<< zerocount<<endl;
  
  return 0;
	
}



void classifynumber(const int number, int &zerocount, int &oddcount, int &evencount)
{
	
  switch(number % 2)
    {
    case 0:
      { 
	evencount++;
	if ( number == 0)
	  zerocount++;
	break;
      }
    default:
      {
	oddcount++;
	break;
      }
    }
			
}

theheapWalker · 12-20-2017, 01:00 PM

your code was copied and an attempt was made to compile it.

gcc didn't recognise iostream.h as a headerfile.

What other header file (that is equivalent to iostream.h) will gcc recognise?

astrogeek · 12-20-2017, 01:18 PM

@theheapWalker:

You continue to exhibit a pattern of seeking out old posts and replying to them without providing any useful information or questions of your own.

If you have questions of your own please post them to your own thread with proper context. Please see the Site FAQ for guidance in participation on this forum.

If this pattern continues your posting privileges may be suspended.

NevemTeve · 12-21-2017, 12:12 AM

@theheapWalker: It is C++, so compile it with g++ But you should know that C++ is still in the experimental phase, so it keeps changing: new compilers are allowed not to compile old code, and vice versa.