[shafqatbaboo]

I want to create a program that convert decimal number to binery
here is my code that not work:

#include <iostream.h>
#include <iomanip.h>

using namespace std;

void Deci2Bin();


int main()
{
	int number1;
	int number2;

	cout<<"======================================="<<endl;
	cout<<"=	  Decimal to Binary Converter	="<<endl;
	cout<<"=======================================\n"<<endl;

	cout<<"Please enter first decimal number : ";
	cin>>number1;
	cout<<"Please enter second decimal number: ";
	cin>>number2;



	cout<<"======================================="<<endl;
	cout<<"First Integer : "<<number1<<"="<<Deci2Bin<<endl;
	cout<<"Second Integer: "<<number2<<"="<<endl;
	return 0;
}
void Deci2Bin()

  int num;
  int bin[25];
  int i;
  for(i=0;num>0;i++)


			{
			bin[i]=num%2;
			num/=2;
			}
			for(--i;i>=0;i--)
			cout<<bin[i];

Please help me.

[bimbolena]

Hi!

Deci2Bin must have a parameter for the number and be called as a function. I've changed that part below, hope it helps.

/Lena

#include <iostream.h>
#include <iomanip.h>

using namespace std;

void Deci2Bin(int num);


int main()
{
	int number1;
	int number2;

	cout<<"======================================="<<endl;
	cout<<"=	  Decimal to Binary Converter	="<<endl;
	cout<<"=======================================\n"<<endl;

	cout<<"Please enter first decimal number : ";
	cin>>number1;
	cout<<"Please enter second decimal number: ";
	cin>>number2;



	cout<<"======================================="<<endl;
	cout<<"First Integer : "<<number1<<"="; 
	Deci2Bin(number2); 
	cout<<endl;
	cout<<"Second Integer: "<<number2<<"=";
	Deci2Bin(number2);
	cout<<endl;
	return 0;
}
void Deci2Bin(int num)
{ 
  int bin[25];
  int i;
  for(i=0;num>0;i++)
			{
			bin[i]=num%2;
			num/=2;
			}
  for(--i;i>=0;i--)
			cout<<bin[i];
}

[computerfox]

this should shed some light...

hope that helps

[shafqatbaboo]

Thanx for helping but it gives me result show below:
when i enter 12 and 8 it give me same result that is 1000

Attached File(s)

•  Image00091.bmp (112.72K)
  Number of downloads: 46

[computerfox]

which code?

[kewlkreator]

DreamInCode has a request that you post your code like . This will keep your post organized and easy to tell apart. Please edit this.

[horace]

shafqatbaboo, on 12 Aug, 2009 - 11:40 AM, said:

Thanx for helping but it gives me result show below:
when i enter 12 and 8 it give me same result that is 1000

in main()

	cout<<"======================================="<<endl;
	cout<<"First Integer : "<<number1<<"=";
	Deci2Bin(number2);
	cout<<endl;
	cout<<"Second Integer: "<<number2<<"=";
	Deci2Bin(number2);
	cout<<endl;
	return 0;

both times you call Deci2Bin() with number2 (hence you get 1000 printed both times) - the first time should be with number1, i.e.

	cout<<"======================================="<<endl;
	cout<<"First Integer : "<<number1<<"=";
	Deci2Bin(number1);
	cout<<endl;
	cout<<"Second Integer: "<<number2<<"=";
	Deci2Bin(number2);
	cout<<endl;
	return 0;
}

in Deci2Bin() a faster alternative to using the % operator

			bin[i]=num%2;

is &, i.e.

			bin[i]=num&1;

This post has been edited by horace: 12 August 2009 - 06:07 AM

[tobix10]

 for(--i;i>=0;i--)
			cout<<bin[i]; 

look at this for statement

[computerfox]

edited

This post has been edited by computerfox: 12 August 2009 - 08:59 AM

[horace]

tobix10, on 12 Aug, 2009 - 02:22 PM, said:

 for(--i;i>=0;i--)
			cout<<bin[i]; 

look at this for statement

what is wrong with it? it prints out the binary value most significant bit first

[Plus]

you know if you're writing a code for others to read, your code should make sense .. unless if you're making it complex for others to reas,

[baavgai]

Code runs fine. You can test it with a loop, if you like.

#include <iostream>

using namespace std;

// pass a number
void Deci2Bin(int num) {
	int bin[25];
	int i;
	
	// load up the array
	for(i=0;num>0;i++) {
		bin[i]=num%2;
		num/=2;
	}
	
	// read it back out backwards
	// note, need to decrement i first
	for(--i;i>=0;i--) {
		cout << bin[i];
	}
}


int main() {
	for(int i=0; i<20; i++) {
		cout << i << "\t";
		Deci2Bin(i);
		cout << endl;
	}
	return 0;
}

A slightly cleaner way would be to use a string. That way you could also return it.

Which got me to thinking, if I really wanted to use an array for this, I'd go with a char array.

void Deci2Bin(int num) {
	const int MaxSize = 65; // you know, an int could be that big + 0
	char s[MaxSize];
	int pos = MaxSize; // init pos
	
	// the trick with pos, it must always point to current
	s[--pos] = 0; // terminate our string
	
	// load up the array
	while(num>0) {
		s[--pos] = (num%2) ? '1':'0';
		num/=2;
	}
	
	char *p = &s[pos]; // fake out cout
	cout << p;
}

You can actually do a recursive solution to this in three lines. I'll leave that as an exercise for the reader.

This post has been edited by baavgai: 12 August 2009 - 11:16 AM

[bimbolena]

Ooops my fault. Typed number2 twice when I made the answer for him. Or can I claim it wa intentional to check and see if he read and understand the code himself?

Lena

horace, on 12 Aug, 2009 - 05:05 AM, said:

shafqatbaboo, on 12 Aug, 2009 - 11:40 AM, said:

Thanx for helping but it gives me result show below:
when i enter 12 and 8 it give me same result that is 1000

in main()

	cout<<"======================================="<<endl;
	cout<<"First Integer : "<<number1<<"=";
	Deci2Bin(number2);
	cout<<endl;
	cout<<"Second Integer: "<<number2<<"=";
	Deci2Bin(number2);
	cout<<endl;
	return 0;

both times you call Deci2Bin() with number2 (hence you get 1000 printed both times) - the first time should be with number1, i.e.

[computerfox]

that's so mean lena lol

any further questions?

[shafqatbaboo]

Thanx very much.
Sir I also want to test AND,OR and Exclusive OR with these two number.
Help me for testing the result. Thankfull to all of you.