C++ While Loop: Hex & Oct, & Dec

Question

I'm currently working on a code that:

takes 2 decimal numbers which are then displayed converted in octal, and hexadecimal, as well as in their original format, in a compact viewing table.

Currently, I'm restricted to a while loop. and the code looks like:

cout << "Enter in two hexadecimal numbers that will be the beginning and end\n";
while (num1 <= num2){
    // takes 2 hexadecimal inputs
    cin >> hex >> num1; cin >> hex >> num2; 

    cout << "Decimal\tOctal\tHexadecimal\n";
    cout << "***********************************\n";

It's not much, but this has been eating away at me for some time. I currently have no idea how to approach this.

Note: I don't know what to increment, or if I need another variable. If you could give advice, or point me in the right direction that would be great.

Answer 1

Firstly, you want to get your values, then loop from num1 to num2 with something like:

cout << "Enter in two hexadecimal numbers that will be the beginning and end\n";
cin >> hex >> num1; cin >> hex >> num2; //takes 2 hexadecimal inputs

while (num1 <= num2) {
    // ... do stuff
    ++num1;
}

Then you probably just want io manipulators as you used for input to output num1 in your different bases in the "do stuff" part of the loop.

Answer 2

One thing - you probably want to start the loop after you read the values

cout << "Enter in two hexadecimal numbers that will be the beginning and end" << endl;
cin >> hex >> num1; cin >> hex >> num2; //takes 2 hexadecimal inputs

while (num1<=num2)
{
   cout << num1 << "  " << oct <<  num1 << "  " << hex << num1 <<endl;
   num1++;
}

Answer 3

I'd probably do something like this...

#include <iomanip>

.........

int num1 = 0;
int num2 = 0;
cout << "Enter number 1: ";
cin >> num1;
cout << "Enter number 2: ";
cin >> num2;

if(num1 > num2){
    cout << "number 1 needs to be smaller than number 2; exiting...";
    return 0;
}

cout << "Decimal\tOctal\tHexadecimal\n";
cout << "***********************************\n";
while(num1 <= num2){
    cout << dec << num1 << " " << oct << num1 << " " << hex << num1 << endl;
    num1++;
}

look into ios flags for c++