hexadecimal

alright so i'm making a program now that takes a decimal number from the user and outputs the number out again but counting in binary, octal, and hexadecimal. I can get binary and octal easily but hexadecimal is hard i don't know how to do it.

any help?

Code:

switch (num % 16) {
    case 10:
       hex = 'A'
       break;
    case 11:
       hex = 'B'
       break;
    case 12:
       hex = 'C'
       break;
    case 13:
       hex = 'D'
       break;
    case 14:
       hex = 'E'
       break;
    case 15:
       hex = 'F'
       break;
}

ok considering the fact that i'm a noob to this, can you tell me how i would apply that switch statement to what i'm trying to do? lol sorry.

Post what you tried.

i haven't really tried anything, i put that code into my program and i don't really know how to code around it so that the user can input 9999 and get the hex number.

> I can get binary and octal easily but hexadecimal is hard
I thought this implied you had some code.

This is what i have so far. I know it's way more complicated than it has to be and i know i use gotos all over the place but bear with me, i'm a noob.

Code:

#include <iostream.h>

main()
{
	int choice1, remainder1, remainder2, remainder3, remainder4, remainder5, remainder6, remainder7, remainder8, remainder9, remainder10, remainder11, remainder12, remainder13, remainder14;
	int base1 = 2;
	int base2 = 8;
	int value, value1, value2, value3, value4, value5, value6, value7, value8, value9, value10, value11, value12, value13, value14;
	char choice2, hex;

A:	cout << "Welcome to the number converter." << endl;
D:	cout << "Enter a number between 0 and 9999. " << endl;
	cin >> value;
	
	if ( value > 9999 )
	{
		cout << "Please enter a number between 0 and 9999." << endl;
		cin.clear();
		cin.ignore();
		cout << endl;
		goto D;
	}
	else if ( value < 0 )
	{
		cout << "That is not a positive number.  Please enter a positive number." << endl;
		cin.clear();
		cin.ignore();
		cout << endl;
		goto D;
	}
	else if ( value > 0 && value < 9999 )
	{
		goto E;
	}
	else
	{
		cout << "Please enter a number Por Favor!" << endl;
		cin.clear();
		cin.ignore();
		cout << endl;
		goto D;
	}

E:	cout << "Now, choose what base you would like to convert to." << endl;
	cout << "   1.) Binary" << endl;
	cout << "   2.) Octal" << endl;
	cout << "   3.) Hexadecimal" << endl;
	cout << "Please enter your choice: ";
	cin >> choice1;

	if (cin.fail())
	{
		cin.clear();
		cin.ignore();
		cout << "Don't enter a letter stupid." << endl;
		goto E;
	}
	
	if (choice1 > 3)
	{
		cin.clear();
		cin.ignore();
		cout << endl << "C'mon idiot it gives you the choices now obey!" << endl;
		goto E;
	}

	if (choice1 < 1)
	{
		cin.clear();
		cin.ignore();
		cout << endl << "C'mon idiot it gives you the choices now obey!" << endl;
		goto E;
	}

	switch ( choice1 )
	{
	case 1:
		value1 = value / base1;
		remainder1 = value % 2;
		value2 = value1 / base1;
		remainder2 = value1 % 2;
		value3 = value2 / base1;
		remainder3 = value2 % 2;
		value4 = value3 / base1;
		remainder4 = value3 % 2;
		value5 = value4 / base1;
		remainder5 = value4 % 2;
		value6 = value5 / base1;
		remainder6 = value5 % 2;
		value7 = value6 / base1;
		remainder7 = value6 % 2;
		value8 = value7 / base1;
		remainder8 = value7 % 2;
		value9 = value8 / base1;
		remainder9 = value8 % 2;
		value10 = value9 / base1;
		remainder10 = value9 % 2;
		value11 = value10 / base1;
		remainder11 = value10 % 2;
		value12 = value11 / base1;
		remainder12 = value11 % 2;
		value13 = value12 / base1;
		remainder13 = value12 % 2;
		value14 = value13 / base1;
		remainder14 = value13 % 2;
		cout << remainder14 << remainder13 << remainder12 << remainder11 << remainder10 << remainder9 << remainder8 << remainder7;
		cout << remainder6 << remainder5 << remainder4 << remainder3 << remainder2 << remainder1;
		cout << endl << endl << "Exclude the zeros to the left of the first 1 digit." << endl;
		break;
	case 2:
		value1 = value / base2;
		remainder1 = value % 8;
		value2 = value1 / base2;
		remainder2 = value1 % 8;
		value3 = value2 / base2;
		remainder3 = value2 % 8;
		value4 = value3 / base2;
		remainder4 = value3 % 8;
		value5 = value4 / base2;
		remainder5 = value4 % 8;
		value6 = value5 / base2;
		remainder6 = value5 % 8;
		value7 = value6 / base2;
		remainder7 = value6 % 8;
		value8 = value7 / base2;
		remainder8 = value7 % 8;
		value9 = value8 / base2;
		remainder9 = value8 % 8;
		value10 = value9 / base2;
		remainder10 = value9 % 8;
		value11 = value10 / base2;
		remainder11 = value10 % 8;
		value12 = value11 / base2;
		remainder12 = value11 % 8;
		value13 = value12 / base2;
		remainder13 = value12 % 8;
		cout << remainder13 << remainder12 << remainder11 << remainder10 << remainder9 << remainder8 << remainder7;
		cout << remainder6 << remainder5 << remainder4 << remainder3 << remainder2 << remainder1;
		cout << endl << endl << "Exclude the zeros to the left of the first whole number digit." << endl;
		break;
	case 3:
		break;
	
	

C:	cout << endl << "Would you like to try again? y or n ";
	cin >> choice2;

	if ( choice2 == 'y' )
	{
		cin.clear();
		cin.ignore();
		cout << endl << endl;
		goto A;
	}
	
	if ( choice2 == 'n' )
	{
		cout << endl << endl;
		goto B;
	}

	if ( choice2 != 'n'||'y' )
	{
		cout << "That ain't right.  try again." << endl;
		cin.clear();
		cout << endl << endl;
		goto C;
	}

B:  cout << "Thanks for.....playing?" << endl;

	return 0;
}

This is fun:

Code:

// For class, eh? Removed.

Don't worry about the string stream if you don't know it. You can do this with plain ol' strings as well.

this is also something i don't understand.

LOL i feel dwarfed by you guys.

Ah... don't feel dwarfed by me. Salem, yes. Me, no.

grrrr with hexadecimal.

this is for a c++ class btw and this is due like....tomorrow.

crap XD

I hope you don't expect to get anything better than an F on that program.

You should really consider using a loop since you can really see an iterative structure in that code.

Code:

while(Number > 0)
{
  Digit = Number % Base;
  PrependToResult(Digit);
  Number /= Base;
}

To convert the number to a hex character:

Code:

char NumberToHex(int Number)
{
  return (Number < 10) ? ('0' + Number) : ('A' + Number - 10);
}

Well, for oct and hex are you allowed to do this:

Code:

int main()
{
    int number;
    cout << "Enter a number: ";
    cin >> number;

    cout << "Oct: " << oct << number << endl;
    cout << "Hex: " << hex << number << endl;

    return 0;
}

I nominate hk_mp5pdw the king of standard C++ keywords and functions.

...and no, I don't think he can do that one.