Letting the user make a choice

[jgush3]

I have written a program that converts a decimal number into binary, hexadecimal, and octal. The program needs to ask the user what they want to convert to and then print the answer. I have tried using if else statements but they create errors.
Here is my code

#include "stdafx.h"
#include <stdio.h>
#include <iostream>
using namespace std;
void binary(int);

int main(void) {
    int number,h,o;
	
    cout << "Enter a positive integer: ";
    cin >> number;
    if (number < 0)
        cout << "That is not a positive integer.\n";
    else {
        cout << number << " converted to binary is: ";
       binary(number);
        cout << endl;

	long int remainder,quotient;
    int i=1,j,temp;
    char hexadecimalNumber[100];

    quotient = number;
    while(quotient!=0){
         temp = quotient % 16;

      if( temp < 10)
           temp =temp + 48;
      else
         temp = temp + 55;
      hexadecimalNumber[i++]= temp;
      quotient = quotient / 16;
  }
    cout<<number<<" converted to hexadecimal is :";
    for(j = i -1 ;j> 0;j--)
     printf("%c",hexadecimalNumber[j]);
	cout<<endl;

  int octalNumber[100],x=1,y;

  quotient = number;

  while(quotient!=0){
      octalNumber[x++]= quotient % 8;
      quotient = quotient / 8;
  }

	cout<<number<<" converted to octal is :";
  for(y = x -1 ;y> 0;y--)
      printf("%d",octalNumber[y]);
  cout<<endl;

    }
	int choice;
	cout<<"Which base would you like to convert to?"<<endl<<"1-Binary"<<endl<<"2-Hex"<<endl<<"3-Octal"<<endl;
	cin>>choice;
	
		
	
		
}
 
void binary(int number) {
    int remainder;
 
    if(number <= 1) {
        cout << number;
        return;
    }
 
 
    remainder = number%2;
    binary(number >> 1);
    cout << remainder;
}

[georgep]

Try putting each conversion into its own function, and instead of using a void function, make it return an int.

There are a number of different ways to give the user a choice. For example, you could use a string, or maybe an int.

eg.

int choice;

cout << "What would you like to convert to?" << endl;
cout << "1-Binary" << endl
     << "2-Hex" << endl
     << "3-Octal" << endl;

cin >> choice;

switch (choice)
{
    case 1:
        cout << binary(choice) << endl;
        break;

    case 2:
        cout << hex(choice) << endl;
        break;

    case 3:
        cout << octal(choice) << endl;
        break;
}

//or alternatively...

if(choice == 1)
    cout << binary(n) << endl;
else if(choice == 2)
    cout << hex(n) << endl;
else if(choice == 3)
    cout << octal(n) << endl;

Using a string would allow the user to type what they want:

string choice;

cout << "What would you like to convert to?" << endl;

cin >> choice;

if(choice == "binary")
    cout << binary(n) << endl;
else if(choice == "hex" || choice == "hexadecimal")
    cout << hex(n) << endl;
else if(choice == "octal")
    cout << octal(n) << endl;

The string option could also be done in a switch statement, as with an int: Wrong!

[Moeljbcp]

Sadly, you can't switch on strings in C++, so you'll have to pass on that. The other ways should work, though.

[jgush3]

yea i figured that I should make hex and octal functions, I went with this route because i couldn't get my original functions to work. I'll try what you said, thankyou

[georgep]

Aah yes, Moeljbcp, my mistake.