Reference array from class in an other class - c++

Question

I'm writing a program that converts decimal numbers into binary, octal and hexadecimal. I'm doing each conversion in different class, but i want to use the binary form of the number which is stored in an array(bin[31]) inside the 1st class. Is there a way to use that array in my other classes? My teacher said i should use references, but i don't know how to do it. My files are:
Binary.h
#ifndef BINARY_H
#define BINARY_H
class Binary{
public:
int num_;
static int bin[31];
int i;
int x;
Binary();
void Set(int temp);
int Get();
void ChangeToBinary();
void ChangeToBinaryComplement();
void TwoComplement();
void PrintBinary();
~Binary();
};
# endif
Binary.cpp
#include <stdio.h>
#include <iostream>
#include "Binary.h"
#include "Octal.h"
using namespace std;
Binary::Binary(){
}
void Binary::Set(int temp){
num_ = temp;
}
int Binary::Get(){
return num_;
}
void Binary::ChangeToBinary(){
x = 1;
for (i=0;i<30;i++){
x*=2;
}
for (i = 0; i<31;i++){
if (num_ -x >= 0){
bin[i] = 1;
num_ = num_ -x;
}
else{
kettes[i] = 0;
} x=x/2;
}
}
void Binary::ChangeToBinaryComplement(){
for (i=0;i<31;i++){
if (bin[i] ==0){
bin[i] = 1;
}
else {
bin[i] = 0;
}
}
}
void Binary::TwoComplement(){
for(i=30;i>0;i--){
if(bin[i] == 0){
bin[i] = 1;
break;
} else{
bin[i] = 0;
}
}
}
void Binary::PrintBinary(){
for (i=0;i<31;i++){
cout << bin[i];
}
cout << " " << endl;
}
Binary::~Binary()
{
}
Octal.h
#ifndef OCTAL_H
#define OCTAL_H
class Octal{
private:
int* oct_ = new int[10];
int i;
public:
Octal();
void ConvertToOctal();
void PrintOctal();
~Octal();
};
#endif
Octal.cpp
#include <stdio.h>
#include <iostream>
#include "Binary.h"
#include "Octal.h"
using namespace std;
Octal::Octal()
{
}
void Octal::ConvertToOctal(){
int k = 0;
int z = 0;
int o = 0;
for(i=0;i<31;i++){
if((help[i] ==1) && (k==0)){
z = z + 4;
k = k + 1;
}
else if((help[i] ==1) && (k==1)){
z = z + 2;
k = k + 1;
}
else if((help[i] ==1) && (k==2)){
z = z + 1;
k = k + 1;
}
else{
k = k + 1;
}
if(k==3){
oct_[o]=z;
z=0;
k=0;
o = o + 1;
}
}
}
void Octal::PrintOctal(){
for(i=0;i<10;i++){
cout << oct_[i];
}
}
Octal::~Octal()
{
}

Answer 1

If you have to use your own classes
You can add a method inside the Binary class that lets you get access to the pointer to the array containing the data. The method would probably look like this:
int getData(){
return bin;
}
You can also access the array directly using Binary::bin, which will also give you a pointer to the first element of the array.
It would be much better tho if you changed the array type from int to bool or char. If you want to do it even better - use the vector< bool > template class. It's basically an array of bools. You can read about it in the C++ Reference
If you just need the funcionality
You should really just use the standard manipulators. There is no real reason to reinvent the wheel. The easiest way to do this is by inputting a number into a stream, and outputing it into a string. Like this:
#include<string> // string
#include<sstream> // stringstream
#include<iostream> // cin, cout
#include<iomanip> // setbase
using namespace std;
int main(){
int number;
cin >> number;
stringstream parser;
parser << setbase(16) << number;
string convertedNumber;
parser >> convertedNumber;
cout << endl << convertedNumber << endl;
return 0;
}
Of course you can change the base inside the setbase manipulator.