Error

[Windwhistles]

Hello everyone,
I am getting an error on line 26.
Error: no match for 'operator<<' in 'std::cout<<factor.Factor::results(fact_number)'

Thanks in advance for your help, I'm new to OOP.

main.cpp

//this program:
//factors a given number

#include <iostream>
#include <cmath>
#include "Declarations.h"

using namespace std;

int fact_number;

int main()
{
    int n;  //holds the number to factor
    Factor factor;  //Factor object


    //get a number from the user
    cout<<"Enter a number.  ";
    cin>>n;

    factor.set_num(n);  //factor the number

    //print the factors
    cout<<"The factors for "<<n<<" are:\n\n";
    cout<<factor.results(fact_number);

    //terminate program
    return 0;
}


//------------------------------------------------------------------------------
//Factor class functions

void Factor::fact()     //factors 'num', stores factors in 'factors'
{
    int i;            //loop variable
    int prime_num=2;  //holds prime numbers


    //factor
    for(i=0; i<MAX_FACTORS && num>prime_num;)
    {
        if(num%prime_num==0)    //this means 'prime_num' is a factor
        {
            factors[i]=prime_num;   //store the factor
            i++;
            num/=prime_num;         //divide 'num' by its factor
        }

        else
        {
            while(!prime(prime_num))    //make 'prime_num' prime
            {
                prime_num++;
            }
        }
    }

    fact_number=i;
}


bool Factor::prime(int n)   //returns true if prime
{
    int i;  //loop variable


    for(i=2; i<=sqrt(n); i++)
    {
        if(n%i==0)  //if not prime
        {
            return false;
        }
    }

    return true;
}


void Factor::results(int a)    //prints the factors
{
    //'a' is how many elements of 'factors' were initialized

    for(int i=0; i<a; i++)
    {
        cout<<factors[i]<<endl;
    }
}

//----------------------------------------------------------------------------- 

Declarations.h

#define MAX_FACTORS 50  //maxium number of factors


//factors a given number
class Factor
{
    private:
        int num;    //holds the number to factor
        int factors[MAX_FACTORS];   //holds the factors of a number 'num'
    public:
        void set_num(int a) //sets 'num'
            {num=a; fact();}
        void results(int a);    //prints the factors
    private:
        void fact();        //factors 'num', stores factors in 'factors'
        bool prime(int n);  //returns true if prime
};

[Moschops]

cout<<factor.results(fact_number);

So you're trying to output the value returned from calling the function results? What kind of object does that function return? Why, none at all!

How can you output an object of type void? It makes no sense. What did you expect to happen?

[Windwhistles]

Thanks for your help Moschops.