[jadu-85]

hello, if anyone could help me in creating a C++ code which i could use on borland builder 6, which would convert Binary input into a Decimal output. Many thanks.
Jadu

[spullen]

wouldn't it just be a for loop, and then break down the binary number and when it is a 1 just add 2^i to a sum variable?

[ByteWyse]

Maybe I'm missing something, but if all you want is a textual representation (in C):

   int v;
   . . .
   // Put the 'binary' value into v.
   . . .
   char cBuffer[16];
   sprintf(cBuffer, "%d", v);

[Xing]

Check this

[jadu-85]

ermm, im new to programming and i have an idea of a do-while loop. so far i have got a main heading, "converting Binary to Decimal", and i set my binary input as char. is that right? then i put the following message "please enter '1' or '0' ". i tried to make a do-while loop for the process of the first input.

for example if i call my input "bin" and also have a counter originally starting from '0'.
i have the folowing equation.... bin*(2^counter)... is that correct?

BTW im using 'iostream' and borland 6

This post has been edited by jadu-85: 28 March 2007 - 04:42 PM

[NickDMax]

if you post your code it is a little easier to see what you have done.

There a lots of methods for converting binary to decimal, its easier then converting back. The basic way to accept and input in any base is to use a variable called an accumulator (that does not have to be its name, that is just what it is in computer science), initalize it to zero, and then in a loop: multiply it by the base, add in the digit.

accumulator := 0;
while (getinput is in the set [0...base-1])
{
	accumulator = accumulator * base + input;
}

There are a couple of catches:
* accumulator probably has a maximum value for its datatype and you need to make sure you do not try to go past it.
* the user input is probably an ascii character so you need to convert it to a number first in C is the user input type is char and you want to get its numeric value use (inputC - '0') to convert from the ascii value to the numeric value.

[jadu-85]

#include <iostream>

using namespace std;

void main()
{
bool bin;
int answer;
int sum;
int counter=1;
char x;
int Dec;

cout<<"Converting Binary To Decimal "<<endl<<endl;



cout<< "Please Enter A Binary Number Of '1' or '0' = ";
cin>>bin;
cout<<endl;


sum = bin * counter;




cout<< "The Decimal Equivilant Is : "<<sum<<endl<<endl;


if(bin=x);
{
//end program
  cout<<endl;
  system("PAUSE");
}
}

its missing lots of parts, but need allot of help. anyone?

[NickDMax]

Well the code does not make a lot of sence to me. Though it seems to work.

First off I would warn you about the bool datatype. bool is really an int, so the user may enter a value other than 1 or 0.

Next there is the line if(bin=x);. This is more or less useless as it means exactly the same thing as bin=x, however x is uninitalized and so bin is whatever. The semicolon at the end of if(bin=x); ends the statement so that the next code in the brackets {} is executed no matter what.

I think what you may have meant was:

if (bin==x)
//end program
  cout<<endl;
  system("PAUSE");
}

Though why would you do that? x is unilitialized, and bin is supposed to be a 1 or a 0, and the program will end anyway.

The program really does not do much since the bin is already and int, which already contains a 1 or a 0 and the line sum = bin * counter could be done with sum=bin just as easily.

You want to convert a binary input (I will assume a string of 1's and 0's) into a value. So your input line has to get a string, not a number (though you could just make a loop so the user inputs 1 bit at a time, more or less like the above program but with a loop).

lets say you did it that way, not very user friendly, but we can actually make it a little better.

int main()
{
	int bin;
	int answer;
	unsigned int sum;
	int counter;
	char x;
	int Dec;

	cout<<"Converting Binary To Decimal "<<endl<<endl;

	counter = 1;
	sum=0;
	do
	{
		cout<< "Please Enter A Binary Number Of '1' or '0' (-1 to exit) = ";
		cin>>bin;
		cout<<endl;
		if (bin == 0 || bin == 1)
		{
			sum = sum * 2 + bin;
			counter++;
		} else if (bin != -1)
		{
			cout << "Invalid entry!" << endl;
		}

	} while (bin != -1 && counter < 32);
	if (counter==32)
	{
		cout << "Sorry can only take 32 bit numbers" <<endl;
	}

	cout<< "The Decimal Equivilant Is : "<<sum<<endl<<endl;


/*	if(bin==x);
	{
	//end program
	  cout<<endl;
	  system("PAUSE");
	}*/
	return 0;
}

This version will work, but it does not stop the user from entering all kinds of data that is not a valid entry, it also forced the user to inter the data in a rather uncomfortable format. But is DOES convert binary to decimal.

A better approch would be to only read in 1 char at a time, see if it is a '1' or a '0' and then convert it to a value. This way the user could enter "10010101" which would be better for the user/customer i.e. teacher and result in a better grade I would think.