Problem with character array and binary addition

[emitremmit]

I am having problems with my program to add and multiply two 4 bit binary numbers. The part in which I am currently having trouble is when I run the program the output for the addition function is not correct. Instead of displaying the correct answer it is just displaying 3 3 3 3. Any help would be greatly appreciated.

Main:

#include "binNum.h"
#include "misc_ops.h"

#include <iostream>
#include <string>
#include <string.h>
using namespace std;

int main()
{
	int i = 0;

	binNum num;
	num.numbers();
	num.addition();
	num.convert(i);

	


	  	//keeps the output window open
	cout << "Press enter to continue \n"; 
	cin.sync();
	cin.ignore();
	char ch = getchar();

  return 0;
}

binNum.h

#ifndef BINNUM_H
#define BINNUM_H

using namespace std;

class binNum
{
	private:
		char num [5], num2 [5], c [5], sum [5];
	int i, j, k, x, carry;
	char  result;
	

  

	public:
	binNum();    //Default constructor
	void numbers();
	void addition();
	void multiplication();
	void convert(int);
	~binNum();


};



#endif

binNum.cpp

#include "binNum.h"		//obtain prototype definitions
#include <iostream>

using namespace std;

binNum::binNum()
{
	i = 0;
	carry = 0;
	k = 0;
	x = 0;
	result = ' ';
	 
	
}

void binNum::numbers()
{
	cout << "Enter a 4 bit binary number entering only 0's and 1's: ";
	for ( i=0; i < 4; i++)
    {
		cin >> num[i];
		
		
		
		break;
		
			
    }
	//cin.get(num[i]);
	cout << "Enter another 4 bit binary number entering only 0's and 1's: ";
	 for (i = 0; i < 4; i++)
    {
        cin >> num2[i];
		
		//break;
    }
	 //cin.get(num2[i]);
}

void binNum::addition() 
{
	


    for(i = 3; i <= 0 ; i--) 
	{
	if (num[i] == '1' && num2[i] == '1' && carry == '1')
	    {
	      c[j] = 1;
	      carry = 1;
		  sum[k]=1;
		  result = sum[k];
		  
	    }
	    else if (num[i] == 1 && num2[i] == 1 && carry == 0)
	    {
	        c[j] = 0;
	        carry = 1;
			sum[k] = 0;
			result = sum[k];
	    }
	    else if (num[i] == 0 && num2[i] == 1 && carry == 0)
	    {
	        c[j] = 1;
	        carry = 0;
			sum[k] = 1;
			result = sum[k];
	    }
	    else if (num[i] == 0 && num2[i] == 1 && carry == 1)
	    {
	      c[j] = 0;
	      carry = 1;
		  sum[k] = 0;
		  result = sum[k];
	    }
	    else if (num[i] == 1 && num2[i] == 0 && carry == 1)
	    {
	      c[j] = 0;
	      carry = 1;
		  sum[k] = 0;
		  result = sum[k];
	    }
	    else if (num[i] == 1 && num2[i] == 0 && carry == 0)
	    {
	      c[j] = 1;
	      carry = 0;
		  sum[k] = 1;
		  result = sum[k];
	    }
	    else if (num[i] == 0 && num2[i] == 0 && carry == 1)
	    {
	      c[j] = 1;
	      carry = 0;
		  sum[k] = 1;
		  result = sum[k];
	    }
	    else if (num[i] == 0 && num2[i] == 0 && carry == 0)
	    {
	      c[j] = 0;
	      carry = 0;
		  sum[k] = 0;
		  result = sum[k];
	    }
	 
	    k--;
	 
	  }
	  c[0] = carry;
	 
	 cout << "\n" "The sum of the two binary numbers is: " << endl;
	  
	
	 for(k = 0; k <= 3; k++)
	  {
		  
		  cout << result;
		  
	 }
	 
cout << endl;

}

/*void binNum::multiplication() 
{

    for(i = 3; i <= 0 ; i--) 
	{
	if (num[i] == '1' && num2[i] == '1' && carry == '1')
	    {
	      c[j] = 1;
	      carry = 1;
		  sum[k]=1;
		  
	    }
	    else if (num[i] == 1 && num2[i] == 1 && carry == 0)
	    {
	        c[j] = 0;
	        carry = 1;
			sum[k] = 0;
	    }
	    else if (num[i] == 0 && num2[i] == 1 && carry == 0)
	    {
	        c[j] = 1;
	        carry = 0;
			sum[k] = 1;
	    }
	    else if (num[i] == 0 && num2[i] == 1 && carry == 1)
	    {
	      c[j] = 0;
	      carry = 1;
		  sum[k] = 0;
	    }
	    else if (num[i] == 1 && num2[i] == 0 && carry == 1)
	    {
	      c[j] = 0;
	      carry = 1;
		  sum[k] = 0;
	    }
	    else if (num[i] == 1 && num2[i] == 0 && carry == 0)
	    {
	      c[j] = 1;
	      carry = 0;
		  sum[k] = 1;
	    }
	    else if (num[i] == 0 && num2[i] == 0 && carry == 1)
	    {
	      c[j] = 1;
	      carry = 0;
		  sum[k] = 1;
	    }
	    else if (num[i] == 0 && num2[i] == 0 && carry == 0)
	    {
	      c[j] = 0;
	      carry = 0;
		  sum[k] = 0;
	    }
	 
	    k--;
	 
	  }
	  c[0] = carry;
	 
	 cout << "\n" "The sum of the two binary numbers is: " << endl;
	  
	
	 for(k = 0; k <= 3; k++)
	  {
		  
		  cout<< num[k];
	 }
	 
cout << endl;

}*/

void binNum::convert (int binary)
	{
	    int hold = 1;
	    int final = 0;
	     
	    while (binary != 0)
	    {
	        if (binary % 2 == 1)
	        {
	            binary = (binary-1)/10;
	            final += hold;
	        }
	         
	        if (binary % 2 == 0)
	        {
	            binary = binary/10;
	        }
	        hold *= 2;
	    }
	    cout << "Base 10 conversion: " << final << endl;;
	}
	 



binNum::~binNum()       // Destructor function definition
{  cout << "press enter to exit"; 
}

[NathanOliver]

On line 50 you are using j without initializing it. Same thing goes for every other time.

[emitremmit]

On line 50 you are using j without initializing it. Same thing goes for every other time.

I initialized j = 0 and now my output is just outputting a blank line.

[WaltP]

Look at your loop definition. Look at the code. Compare variables.

Also, if you add num[i], num2[i], and carry, you get a value from 0 to 3. Look at your IFs to see if you do different things when you get 2. Or 1. etc. If you don't do different things, you probably don't need so many comparisons.

I'll bet you can compress that whole section (48-109) into less than 10 lines with a little thought.

[emitremmit]

thanks for the help I figured it out